Contact lens and detection method

A contact lens according to an embodiment of the present disclosure includes a lens section attachable to an eyeball, and one or a plurality of structure portions provided in the lens section and intended to accumulate tears. This makes it possible to, for example, measure an absorption spectrum of the tears, by emitting light toward the tears accumulated in the one or plurality of structure portions.

TECHNICAL FIELD

The present disclosure relates to a contact lens and a detection method.

BACKGROUND ART

Typically, as methods of acquiring biological information, there are an invasive type and a non-invasive type. Examples of the invasive type include a method of collecting blood and analyzing the blood by electrochemical reaction. On the other hand, examples of the non-invasive type include a method of emitting light from above skin and analyzing blood on the basis of an absorption spectrum of blood within blood vessels, and a method of collecting tears or sweat and analyzing the collected tears or sweat using various means.

CITATION LIST

Patent Literature

PTL 1: United States Unexamined Patent Application Publication No. 2012/0245444

SUMMARY OF THE INVENTION

The invasive type has such an issue that a burden placed on a body is large. On the other hand, among the methods of the non-invasive type, the method of emitting light from above skin has such an issue that light absorption inside the skin is large, and measurement is not easy, and further, it is not easy to separate body-movement noise and a signal of a detection target. Among the methods of the non-invasive type, the method of analyzing tears or sweat described in the above-mentioned PTL has such an issue that long-term stability and heat resistance are not favorable because an electrode includes a biological material. The above-mentioned PTL also proposes configuring an electrode using an artificial composition, but in a case where an electrode includes such a material, there is such an issue that the electrode exhibits a weak response to a substance other than a detection target as well, or the electrode is easily affected by a coexistence substance or pH in a solution. It is therefore desirable to provide a contact lens and a detection method that make it possible to perform analysis with high accuracy while keeping a burden on a body small.

A contact lens according to an embodiment of the present disclosure includes a lens section attachable to an eyeball, and one or a plurality of structure portions provided in the lens section and intended to accumulate tears.

In the contact lens according to the embodiment of the present disclosure, the one or plurality of structure portions intended to accumulate tears is provided in the lens section. This makes it possible to, for example, measure an absorption spectrum of the tears, by emitting light toward the tears accumulated in the one or plurality of structure portions. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small.

A detection method according to an embodiment of the present disclosure includes the following two.

(1) Emitting light toward tears accumulated in one or a plurality of structure portions in a contact lens that includes a lens section attachable to an eyeball, and the one or plurality of structure portions provided in the lens section and intended to accumulate tears
(2) Detecting, through the tears accumulated in the one or plurality of structure portions, transmitted light transmitted by the contact lens, reflected light reflected by the contact lens, diffracted-transmitted light diffracted and transmitted by the contact lens, or diffracted-reflected light diffracted and reflected by the contact lens, of the light emitted toward the tears accumulated in the one or plurality of structure portions

In the detection method according to the embodiment of the present disclosure, the transmitted light transmitted by the contact lens, the reflected light reflected by the contact lens, the diffracted-transmitted light diffracted and transmitted by the contact lens, or the diffracted-reflected light diffracted and reflected by the contact lens, of the light emitted toward the tears accumulated in the one or plurality of structure portions provided in the lens section, is detected through the tears accumulated in the one or plurality of structure portions. This makes it possible to, for example, measure an absorption spectrum of the tears. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small.

According to the contact lens in the embodiment of the present disclosure, the one or plurality of structure portions intended to accumulate tears is provided in the lens section, and therefore a burden on a body is small, and it is possible to perform analysis with high accuracy.

According to the detection method in the embodiment of the present disclosure, the transmitted light transmitted by the contact lens, the reflected light reflected by the contact lens, the diffracted-transmitted light diffracted and transmitted by the contact lens, or the diffracted-reflected light diffracted and reflected by the contact lens, of the light emitted toward the tears accumulated in the one or plurality of structure portions provided in the lens section, is detected through the tears accumulated in the one or plurality of structure portions, and therefore a burden on a body is small, and it is possible to perform analysis with high accuracy.

It is to be noted that effects of the present disclosure are not limited to those described above, and may be any of effects described in the present specification.

MODES FOR CARRYING OUT THE INVENTION

Some embodiments of the present disclosure are described below in detail with reference to the drawings. It is to be noted that the description is given in the following order.

1. First Embodiment

An example in which a channel that accumulates tears is provided in a lens section (FIG. 1toFIG. 6)

2. Modification Examples of First Embodiment

Modification Example A

An example in which a reflection layer is provided in the lens section (FIG. 8toFIG. 11)

Modification Example B

An example in which a diffraction element is provided in the lens section (FIG. 14toFIG. 17)

Modification Example C

An example in which the reflection layer and the diffraction element are provided in the lens section (FIG. 20,FIG. 21,FIG. 23, andFIG. 24)

Modification Example D

An example in which the channel of the lens section has a prism shape (FIG. 29toFIG. 44)

Modification Example E

An example in which a suction chamber is coupled to the channel of the lens section (FIG. 43andFIG. 44)

Modification Example F

An example in which a suction chamber and a storage chamber are coupled to the channel of the lens section (FIG. 45)

Modification Example G

An example in which a measurement device and a medicinal-solution supply device are provided in glasses (FIG. 46)

3. Second Embodiment

An example in which a channel that accumulates tears and doubles as a light-guiding path is provided in a lens section (FIG. 47toFIG. 52)

4. Modification Examples of Second Embodiment

An example in which an index is provided (FIG. 53toFIG. 57)

An example in which a sealing layer is provided (FIG. 58)

1. First Embodiment

A contact lens1according to a first embodiment of the present disclosure is described.FIG. 1illustrates an example of a state where the contact lens1is attached to an eyeball100.FIG. 2illustrates an example of a cross-sectional configuration of the contact lens1and the eyeball100. The contact lens1includes a lens section10attachable to the eyeball100, and one or a plurality of structure portions20provided in the lens section10. The one or plurality of structure portions20is a structure intended to accumulate tears.

The lens section10has a curved-plane shape that resembles a surface shape of the eyeball100. The lens section10is, for example, circular when viewed from front. The lens section10has a diameter having a value larger than that of a diameter of an outer edge of an iris110. The lens section10may be a lens having an eyesight correction function intended to correct nearsightedness, farsightedness, astigmatism, etc., or may be a lens not having such an eyesight correction function.

The one or plurality of structure portions20is formed, for example, to avoid a middle of the lens section10. The one or plurality of structure portions20is formed, for example, as illustrated inFIG. 3AtoFIG. 3G, to avoid a point opposed to a pupil120, when the contact lens1is attached to the eyeball100. The one or plurality of structure portions20includes, for example, a channel21provided inside the lens section10. The channel21has, for example, a spiral shape around the middle of the lens section10, as illustrated inFIG. 3AtoFIG. 3D. The channel21may be formed, for example, in a circular pattern as illustrated inFIG. 3AtoFIG. 3C, or may be formed, for example, in a quadrangle pattern as illustrated inFIG. 3D. The lens section10may be, for example, provided with the one structure portion20(i.e., the one channel21) as illustrated inFIG. 3AtoFIG. 3D, or may be, for example, provided with the two structure portions20(i.e., the two channels21) as illustrated inFIG. 3EtoFIG. 3G.

It is to be noted that, in a case where the lens section10is provided with the two structure portions20(i.e., the two channels21), the two structure portions20(i.e., the two channels21) may be disposed at respective positions opposed to each other with the middle of the lens section10interposed therebetween. Further, in this case, the channel21may have, for example, a zigzag shape as illustrated inFIG. 3EtoFIG. 3G. Furthermore, in this case, for example, as illustrated inFIG. 3FandFIG. 3G, a pair of an inlet21A and an outlet21B provided in the one structure portion20(i.e., the one channel21) and a pair of the inlet21A and the outlet21B provided in the other structure portion20(i.e., the other channel21) may be disposed at respective positions that have left-right symmetry with respect to the middle of the lens section10. At this time, further, each of the inlets21A may be disposed at a position close to an edge of the lens section10, in the channel21provided with the inlet21A. Furthermore, as for the inlet21A and the outlet21B, in the structure portion20relatively close to a lacrimal gland when the contact lens1is attached to the eyeball100, the inlet21A may be configured to be disposed at a position relatively close to the lacrimal gland as compared with the outlet21B. It is to be noted that, inFIG. 3F, each of the inlets21A and each of the outlets21B are each disposed at a position close to the edge of the lens section10, in both of the structure portions20. Further, inFIG. 3G, each of the inlets21A is disposed at a position close to the edge of the lens section10, and each of the outlets21B is disposed at a position close to the middle of the lens section10, in both of the structure portions20.

Incidentally, the channel21includes, for example, the inlet21A for tears and the outlet21B for tears, as illustrated inFIG. 3AtoFIG. 3GandFIG. 4. The inlet21A and the outlet21B are exposed, for example, on a surface on side to be in contact with the eyeball100, of the lens section10. It is to be noted that at least one of the inlet21A or the outlet21B may be exposed on a surface on side not to be in contact with the eyeball100, of the lens section10. The inlet21A is, for example, disposed at a position close to the edge of the lens section10, in the channel21. In other words, the inlet21A is, for example, disposed at a position relatively close to the lacrimal gland as compared with the outlet21B, when the contact lens1is attached to the eyeball100. The channel21includes an inflow path21fcoupled to the inlet21A, and a discharge path21ecoupled to the inflow path21fand the outlet21B. It is preferable that the inflow path21fhave, for example, a width that makes it possible to draw tears in by a capillary phenomenon, and it is preferable that the discharge path21ehave, for example, a width wider than that of the inflow path21f. The width of the discharge path21eis, for example, a distance that does not cause (or makes it difficult to cause) the capillary phenomenon. The channel21is provided, for example, inside the lens section10, as illustrated inFIG. 4.

FIG. 5illustrates an example of a schematic configuration of a measurement device2intended to measure a component of tears accumulated in the contact lens1. The measurement device2corresponds to a specific example of a “detection device” of the present disclosure. The measurement device2includes, for example, a support section30that supports the contact lens1having tears accumulated in the one or plurality of structure portions20, and a light source section40that emits light toward the tears accumulated in the one or plurality of structure portions20in the contact lens1. The measurement device2further includes, for example, a light receiving section50that receives light (transmitted light Lb) transmitted by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the light (irradiation light La) emitted from the light source section40. The measurement device2further includes, for example, a signal processing section60that determines a state of a living body by analyzing a detection signal outputted from the light receiving section50, and a display section70that displays a result determined by the signal processing section60. The display section70may be omitted. In this case, the measurement device2includes, for example, a communication section that outputs the result determined by the signal processing section60to an external apparatus with a display section.

The light source section40includes, for example, a light source with a single wavelength or a plurality of wavelengths. Examples of the light source included in the light source section40include a laser with a single wavelength, a laser with a plurality of wavelengths, an LED with a single wavelength, an LED with a plurality of wavelengths, an LED with white light, UV light, visible light, or infrared light, etc. The light receiving section50includes, for example, a photodiode, etc. The signal processing section60includes, for example, an integrated circuit IC that executes a measurement procedure described later, etc. The display section70displays, for example, an image on the basis of an image signal from the signal processing section60.

Next, an example of the measurement procedure in the measurement device2is described.FIG. 6illustrates an example of the measurement procedure in the measurement device2. First, a user attaches the contact lens1to the eyeball100of the user. Then, tears are accumulated in the one or plurality of structure portions20(the channel21) provided in the contact lens1, by utilizing, for example, the capillary phenomenon. Next, the user removes the contact lens1having the tears accumulated in the one or plurality of structure portions20from the eyeball100, and attaches the removed contact lens1to the measurement device2(step S101). Specifically, the user allows the support section30to support the contact lens1having the tears accumulated in the one or plurality of structure portions20. As a result, for example, the contact lens1is fixed to the support section30.

Next, the user activates the measurement device2. Then, the light source section40emits the light (the irradiation light La) toward the tears accumulated in the one or plurality of structure portions20(the channel21) in the contact lens1, and the light receiving section50detects the light (the transmitted light Lb) through the contact lens1(step S102). Specifically, the light receiving section50detects the light (the transmitted light Lb) transmitted by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the transmitted light Lb to the signal processing section60.

Next, the signal processing section60analyzes the inputted detection signal, and determines the state of the living body (step S103). Specifically, the signal processing section60derives an absorption spectrum of the tears on the basis of the inputted detection signal, and estimates, for example, a type and a concentration of a component included in the tears, from the derived absorption spectrum. The signal processing section60determines the state of the living body, on the basis of the estimated type and concentration of the component of the tears. The signal processing section60outputs a determination result to the display section70as an image signal. The display section70displays an image (the determination result) on the basis of the image signal inputted from the signal processing section60. It is to be noted that the determination of the state of the living body may be performed by an external apparatus. In this case, the signal processing section60may analyze the inputted detection signal, and output an analysis result to the external apparatus through a communication section.

FIG. 7illustrates an example of an absorption spectrum of each of water, glucose, protein, and lipid.FIG. 7illustrates an example of an absorption spectrum when water, glucose, protein, or lipid is included in a sample at a predetermined concentration. The signal processing section60compares the obtained absorption spectrum and, for example, the absorption spectrum of glucose, protein, or lipid illustrated inFIG. 7, and determines an analogy therebetween. As a result, for example, in a case where the obtained absorption spectrum is similar to the absorption spectrum of glucose, the signal processing section60determines that glucose is included in the tears. Further, the signal processing section60estimates the concentration of glucose included in the tears, by comparing a peak value of the obtained absorption spectrum and a peak value of glucose illustrated inFIG. 7. In this way, the measurement device2determines the state of the living body from the tears.

Next, effects of the contact lens1and the measurement device2of the present embodiment are described.

Typically, as methods of acquiring biological information, there are an invasive type and a non-invasive type. Examples of the invasive type include a method of collecting blood and analyzing the blood by electrochemical reaction. On the other hand, examples of the non-invasive type include a method of emitting light from above skin and analyzing blood on the basis of an absorption spectrum of blood within blood vessels, and a method of collecting tears or sweat and analyzing the collected tears or sweat using various means.

The invasive type has such an issue that a burden placed on a body is large. On the other hand, among the methods of the non-invasive type, the method of emitting light from above skin has such an issue that light absorption inside the skin is large, and measurement is not easy, and further, it is not easy to separate body-movement noise and a signal of a detection target. Among the methods of the non-invasive type, the method of analyzing tears or sweat described in the above-mentioned PTL has such an issue that long-term stability and heat resistance are not favorable because an electrode includes a biological material. The above-mentioned PTL also proposes configuring an electrode using an artificial composition, but in a case where an electrode includes such a material, there is such an issue that the electrode exhibits a weak response to a substance other than a detection target as well, or the electrode is easily affected by a coexistence substance or pH in a solution.

In contrast, in the contact lens1of the present embodiment, the lens section10is provided with the one or plurality of structure portions20intended to accumulate tears. This makes it possible to, for example, measure the absorption spectrum of the tears, by emitting the light toward the tears accumulated in the one or plurality of structure portions20. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small. This makes it possible to perform analysis with high accuracy while keeping a burden on a body small.

Further, in the present embodiment, the one or plurality of structure portions20is formed to avoid the middle of the lens section10. This makes it possible to prevent a view from being blocked by the one or plurality of structure portions20, thereby making it possible to collect the tears of the user while the user uses the contact lens1in everyday life.

Furthermore, in the present embodiment, the one or plurality of structure portions20includes the channel21provided inside the lens section10. This makes it possible to prevent formation of projections and depressions on the surface of the lens section10due to presence of the channel21, thereby making it possible to avoid deterioration of usability of the contact lens1for the user due to the presence of the channel21.

Further, in the present embodiment, the channel21includes the inflow path21fthat makes it possible to draw the tears in by the capillary phenomenon, and further includes the discharge path21ehaving the width wider than that of the inflow path21f. This makes it possible to collect the tears efficiently.

Furthermore, in the present embodiment, in a case where an entrance of the inflow path21fis disposed at a position close to the edge of the lens section10in the channel21, it is possible to collect the tears efficiently, in a process where the tears flow from the lacrimal gland to a lacrimal point. Further, in the present embodiment, in a case where: the two structure portions20(i.e., the two channels21) are disposed at the respective positions opposed to each other with the middle of the lens section10interposed therebetween; the pair of the inlet21A and the outlet21B provided in the one structure portion20(i.e., the one channel21) and the pair of the inlet21A and the outlet21B provided in the other structure portion20(i.e., the other channel21) are disposed at the respective positions that have left-right symmetry with respect to the middle of the lens section10; each of the inlets21A is disposed at the position close to the edge of the lens section10, in the channel21provided with the inlet21A; and the inlet21A in the structure portion20relatively close to the lacrimal gland is disposed at the position relatively close to the lacrimal gland as compared with the outlet21B, when the contact lens1is attached to the eyeball100, it is possible to collect the tears efficiently in the process where the tears flow from the lacrimal gland to the lacrimal point, on whichever side, left side or right side, the contact lens1is used for the eyeball100.

Moreover, in the present embodiment, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20, the light (the transmitted light Lb) transmitted by the contact lens1is detected by the light receiving section50, through the tears accumulated in the one or plurality of structure portions20. This makes it possible to, for example, measure the absorption spectrum of the tears, by emitting the light toward the tears accumulated in the one or plurality of structure portions20. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small. This makes it possible to perform analysis with high accuracy while keeping a burden on a body small.

2. Modification Examples of First Embodiment

Next, modification examples of the contact lens1and the measurement device2according to the first embodiment are described.

Modification Example A

FIG. 8andFIG. 9illustrate a modification example of the contact lens1inFIG. 2. In the present modification example, the contact lens1further includes a reflection layer22disposed to be opposed to the channel21in a thickness direction of the lens section10. The reflection layer22is configured to enable reflection of the light from the light source section40, and includes, for example, a dielectric multilayer film, a metallic film, a hologram, etc. The reflection layer22is disposed, for example, on the surface (a convex-shaped surface10A) on the side not to be in contact with the eyeball100, of the lens section10, or the surface (a concave-shaped surface10B) on the side to be in contact with the eyeball100, of the lens section10. It is to be noted that, for example, as illustrated inFIG. 10andFIG. 11, the reflection layer22may be formed inside the lens section10. At this time, the reflection layer22may be provided in contact with the surface of the channel21, or may be provided to be a portion of an inner surface of the channel21.

FIG. 12illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 8andFIG. 10. It is to be noted that the contact lens1inFIG. 8is exemplified inFIG. 12.FIG. 13illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 9andFIG. 11. It is to be noted that the contact lens1inFIG. 9is exemplified inFIG. 13. The measurement device2includes, for example, the support section30that supports the contact lens1having the tears accumulated in the one or plurality of structure portions20, and the light source section40that emits the light toward the tears accumulated in the one or plurality of structure portions20in the contact lens1. The measurement device2further includes, for example, the light receiving section50that receives light (reflected light Lc) reflected by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the light (the irradiation light La) emitted from the light source section40. The measurement device2further includes, for example, the signal processing section60and the display section70. The display section70may be omitted. In this case, the measurement device2includes, for example, a communication section that outputs a determination result or an analysis result obtained by the signal processing section60to an external apparatus with a display section.

Next, an example of the measurement procedure in the measurement device2is described. First, the user attaches the contact lens1to the eyeball100of the user. Then, the tears are accumulated in the one or plurality of structure portions20(the channel21) provided in the contact lens1, by utilizing, for example, the capillary phenomenon. Next, the user removes the contact lens1having the tears accumulated in the one or plurality of structure portions20from the eyeball100, and attaches the removed contact lens1to the measurement device2(step S101). Specifically, the user allows the support section30to support the contact lens1having the tears accumulated in the one or plurality of structure portions20. As a result, for example, the contact lens1is fixed to the support section30.

Next, the user activates the measurement device2. Then, the light source section40emits the light (the irradiation light La) toward the tears accumulated in the one or plurality of structure portions20(the channel21) in the contact lens1, and the light receiving section50detects the light (the reflected light Lc) through the contact lens1(step S102). Specifically, the light receiving section50detects the light (the reflected light Lc) transmitted by the tears accumulated in the one or plurality of structure portions20, reflected by the reflection layer22, and transmitted by the accumulated tears again, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the reflected light Lc to the signal processing section60. The signal processing section60analyzes the inputted detection signal, and determines the state of the living body using, for example, the above-described analysis method (step S103).

In the present modification example, the reflection layer22disposed to be opposed to the channel21in the thickness direction of the lens section10is provided. This makes it possible to dispose the light receiving section50on the same side as the side where the light source section40is disposed, in a positional relationship with the contact lens1, thereby making it unnecessary to provide a space for the light receiving section50on the side opposite to the side where the light source section40is disposed, in the positional relationship with the contact lens1. As a result, because it is not necessary to provide the space for the light receiving section50on the side opposite to the side where the light source section40is disposed, in the positional relationship with the contact lens1, it is possible to downsize the measurement device2accordingly. Further, in a case where the reflection layer22is formed inside the lens section10, the reflection layer22does not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example B

FIG. 14andFIG. 15illustrate a modification example of the contact lens1inFIG. 2. In the present modification example, the contact lens1further includes a diffraction element23disposed to be opposed to the channel21in the thickness direction of the lens section10. The diffraction element23is configured to allow refraction of the light from the light source section40in a predetermined direction, and includes, for example, a holo-graphic optical element (HOE: Holo-graphic Optical Element). The diffraction element23is disposed, for example, on the surface (the concave-shaped surface10B) on the side to be in contact with the eyeball100, of the lens section10, or on the surface (the convex-shaped surface10A) on the side not to be in contact with the eyeball100, of the lens section10. It is to be noted that, for example, as illustrated inFIG. 16andFIG. 17, the diffraction element23may be formed inside the lens section10. At this time, the diffraction element23may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21.

FIG. 18illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 14andFIG. 16. It is to be noted that the contact lens1inFIG. 14is exemplified inFIG. 18.FIG. 19illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 15andFIG. 17. It is to be noted that the contact lens1inFIG. 15is exemplified inFIG. 19. The measurement device2includes, for example, the support section30that supports the contact lens1having the tears accumulated in the one or plurality of structure portions20, and the light source section40that emits the light toward the tears accumulated in the one or plurality of structure portions20in the contact lens1. The measurement device2further includes, for example, the light receiving section50that receives light (diffracted-transmitted light Ld) diffracted and transmitted by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the light (the irradiation light La) emitted from the light source section40. The measurement device2further includes, for example, the signal processing section60and the display section70. The display section70may be omitted. In this case, the measurement device2includes, for example, a communication section that outputs a determination result or an analysis result obtained by the signal processing section60to an external apparatus with a display section.

Next, an example of the measurement procedure in the measurement device2is described. First, the user attaches the contact lens1to the eyeball100of the user. Then, the tears are accumulated in the one or plurality of structure portions20(the channel21) provided in the contact lens1, by utilizing, for example, the capillary phenomenon. Next, the user removes the contact lens1having the tears accumulated in the one or plurality of structure portions20from the eyeball100, and attaches the removed contact lens1to the measurement device2(step S101). Specifically, the user allows the support section30to support the contact lens1having the tears accumulated in the one or plurality of structure portions20. As a result, for example, the contact lens1is fixed to the support section30.

Next, the user activates the measurement device2. Then, the light source section40emits the light (the irradiation light La) toward the tears accumulated in the one or plurality of structure portions20(the channel21) in the contact lens1, and the light receiving section50detects the light (the diffracted-transmitted light Ld) through the contact lens1(step S102). Specifically, the light receiving section50detects the light (the diffracted-transmitted light Ld) diffracted by the diffraction element23and transmitted by the tears accumulated in the one or plurality of structure portions20, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the diffracted-transmitted light Ld to the signal processing section60. The signal processing section60analyzes the inputted detection signal, and determines the state of the living body using, for example, the above-described analysis method (step S103). It is to be noted that the determination of the state of the living body may be performed by an external apparatus. In this case, the signal processing section60may analyze the inputted detection signal, and output an analysis result to the external apparatus through a communication section.

In the present modification example, the diffraction element23disposed to be opposed to the channel21in the thickness direction of the lens section10is provided. This makes it possible to separate and remove light other than desirable light by diffraction, thereby making it possible to, for example, measure the absorption spectrum of the tears with accuracy. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small. This makes it possible to perform analysis with high accuracy while keeping a burden on a body small. Further, in a case where the diffraction element23is formed inside the lens section10, the diffraction element23does not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example C

FIG. 20illustrates a modification example of the contact lens1inFIG. 2. In the present modification example, the contact lens1further includes the reflection layer22and the diffraction element23. The reflection layer22and the diffraction element23are both disposed to be opposed to the channel21in the thickness direction of the lens section10. The reflection layer22is disposed on the surface (the convex-shaped surface10A) on the side not to be in contact with the eyeball100, of the lens section10. The diffraction element23is disposed on the surface (the concave-shaped surface10B) on the side to be in contact with the eyeball100, of the lens section10. It is to be noted that, for example, as illustrated inFIG. 21, the reflection layer22and the diffraction element23may be formed inside the lens section10. At this time, the reflection layer22and the diffraction element23may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21.

FIG. 22illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 20andFIG. 21. It is to be noted that the contact lens1inFIG. 20is exemplified inFIG. 22. The measurement device2includes, for example, the support section30that supports the contact lens1having the tears accumulated in the one or plurality of structure portions20, and the light source section40that emits the light toward the tears accumulated in the one or plurality of structure portions20in the contact lens1. The measurement device2further includes, for example, the light receiving section50that receives light (diffracted-reflected light Le) diffracted and reflected by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the light (the irradiation light La) emitted from the light source section40. The measurement device2further includes, for example, the signal processing section60and the display section70. The display section70may be omitted. In this case, the measurement device2includes, for example, a communication section that outputs a determination result or an analysis result obtained by the signal processing section60to an external apparatus with a display section.

Next, an example of the measurement procedure in the measurement device2is described. First, the user attaches the contact lens1to the eyeball100of the user. Then, the tears are accumulated in the one or plurality of structure portions20(the channel21) provided in the contact lens1, by utilizing, for example, the capillary phenomenon. Next, the user removes the contact lens1having the tears accumulated in the one or plurality of structure portions20from the eyeball100, and attaches the removed contact lens1to the measurement device2(step S101). Specifically, the user allows the support section30to support the contact lens1having the tears accumulated in the one or plurality of structure portions20. As a result, for example, the contact lens1is fixed to the support section30.

Next, the user activates the measurement device2. Then, the light source section40emits the light (the irradiation light La) toward the tears accumulated in the one or plurality of structure portions20(the channel21) in the contact lens1, and the light receiving section50detects the light (the diffracted-reflected light Le) through the contact lens1(step S102). Specifically, the light receiving section50detects the light (the diffracted-reflected light Le) diffracted by the diffraction element23, transmitted by the tears accumulated in the one or plurality of structure portions20, reflected by the reflection layer22, and transmitted by the accumulated tears and diffracted by the diffraction element23again, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the diffracted-reflected light Le to the signal processing section60. The signal processing section60analyzes the inputted detection signal, and determines the state of the living body using, for example, the above-described analysis method (step S103).

In the present modification example, the reflection layer22and the diffraction element23are provided. This makes it possible to dispose the light receiving section50on the same side as the side where the light source section40is disposed, in the positional relationship with the contact lens1, thereby making it unnecessary to provide a space for the light receiving section50on the side opposite to the side where the light source section40is disposed, in the positional relationship with the contact lens1. As a result, because it is not necessary to provide the space for the light receiving section50on the side opposite to the side where the light source section40is disposed, in the positional relationship with the contact lens1, it is possible to downsize the measurement device2accordingly. Further, in a case where the reflection layer22and the diffraction element23are formed inside the lens section10, the reflection layer22and the diffraction element23do not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example D

FIG. 23illustrates a modification example of the contact lens1inFIG. 2. In the present modification example, the contact lens1further includes the reflection layer22and the diffraction element23. The reflection layer22and the diffraction element23are both disposed to be opposed to the channel21in the thickness direction of the lens section10. In the present modification example, the reflection layer22is disposed on the surface (the concave-shaped surface10B) on the side to be in contact with the eyeball100, of the lens section10. The reflection layer22is disposed at a position closer to the eyeball100than the channel21is when the contact lens1is attached to the eyeball100. The diffraction element23is disposed on the surface (the convex-shaped surface10A) on the side not to be in contact with the eyeball100, of the lens section10. The diffraction element23is disposed at a position farther from the eyeball100than the channel21is when the contact lens1is attached to the eyeball100. It is to be noted that, for example, as illustrated inFIG. 24, the reflection layer22and the diffraction element23may be formed inside the lens section10. At this time, the reflection layer22and the diffraction element23may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21.

FIG. 25illustrates an example of a schematic configuration of the measurement device2intended to measure the component of the tears accumulated in the contact lens1in each ofFIG. 23andFIG. 24. It is to be noted that the contact lens1inFIG. 23is exemplified inFIG. 25. In the present modification example, the measurement device2measures the component of the tears accumulated in the contact lens1remaining attached to the eyeball100. The measurement device2includes, for example, the light source section40that emits the light toward the tears accumulated in the one or plurality of structure portions20in the contact lens1. At this time, the user sets an optical axis of the irradiation light La to prevent most of the irradiation light La from entering a retina within the eyeball100even if the light (the irradiation light La) emitted from the light source section40enters the eyeball100without intervention of the diffraction element23. In other words, it is preferable to allow the irradiation light La to enter the diffraction element23at a considerably shallow angle.

The measurement device2further includes, for example, the light receiving section50that receives the light (the diffracted-reflected light Le) diffracted and reflected by the contact lens1, through the tears accumulated in the one or plurality of structure portions20, of the irradiation light La. The measurement device2further includes, for example, the signal processing section60and the display section70. The display section70may be omitted. In this case, the measurement device2includes, for example, a communication section that outputs a determination result or an analysis result obtained by the signal processing section60to an external apparatus with a display section.

Next, an example of a measurement procedure in the measurement device2is described.FIG. 26illustrates an example of the measurement procedure in the measurement device2. First, the user attaches the contact lens1to the eyeball100of the user (step S201). Then, the tears are accumulated in the one or plurality of structure portions20(the channel21) provided in the contact lens1, by utilizing, for example, the capillary phenomenon. Next, the user installs the measurement device2at a predetermined position, while the contact lens1having the tears accumulated in the one or plurality of structure portions20remains attached to the eyeball100. Specifically, the user adjusts a position and an orientation of the measurement device2with respect to the contact lens1to allow the irradiation light La to enter the diffraction element23at a considerably shallow angle.

Next, the user activates the measurement device2. Then, the light source section40emits the light (the irradiation light La) toward the tears accumulated in the one or plurality of structure portions20(the channel21) in the contact lens1in a state of being attached to the eyeball100, and the light receiving section50detects the light (the diffracted-reflected light Le) through the contact lens1(step S202). Specifically, the light receiving section50detects the light (the diffracted-reflected light Le) diffracted by the diffraction element23, transmitted by the tears accumulated in the one or plurality of structure portions20, reflected by the reflection layer22, and transmitted by the accumulated tears and diffracted by the diffraction element23again, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the diffracted-reflected light Le to the signal processing section60. The signal processing section60analyzes the inputted detection signal, and determines the state of the living body using, for example, the above-described analysis method (step S203).

In the present modification example, the reflection layer22and the diffraction element23are provided. This makes it possible to dispose the light receiving section50on the same side as the side where the light source section40is disposed, in the positional relationship with the contact lens1, thereby making it unnecessary to provide a space for the light receiving section50on the support section30. As a result, because it is not necessary to provide the space for the light receiving section50on the support section30, it is possible to downsize the measurement device2accordingly. Further, in the present modification example, the diffraction element23is disposed on the surface (the convex-shaped surface) on the side not to be in contact with the eyeball100, of the lens section10. This makes it possible to measure the absorption spectrum of the tears while the contact lens1remains attached to the eyeball100. Moreover, in a case where the reflection layer22and the diffraction element23are formed inside the lens section10, the reflection layer22and the diffraction element23do not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

In the present modification example, the measurement device2may be, for example, built in a mobile terminal3, as illustrated inFIG. 27. This makes it possible to carry the measurement device2easily. Further, in the present modification example, the measurement device2may be built in, for example, glasses4, as illustrated inFIG. 28. At this time, the glasses4include a lens frame41, and a temple42rotatably fixed to an end portion of the lens frame41. The measurement device2in the present modification example is provided, for example, in the temple42. In this way, in the case where the measurement device2is built in the glasses4, the user is enabled to adjust the position and the orientation of the measurement device2, only by wearing the glasses4. It is to be noted that the glasses4may be provided with or may not be provided with lenses.

Modification Example E

FIG. 29andFIG. 30illustrate a modification example of the channel21of the contact lens1according to the foregoing embodiment.FIG. 29illustrates an example of an optical path in a state where tears with a low concentration of a detection target substance are accumulated in the channel21.FIG. 30illustrates an example of an optical path in a state where tears with a high concentration of the detection target substance are accumulated in the channel21. It is to be noted that, as illustrated inFIG. 23andFIG. 24, a difference (a refractive index difference) between a refractive index of the tears and a refractive index of the lens section10changes depending on the concentration of the detection target substance included in the tears. Further, as illustrated inFIG. 24, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10may become substantially zero when the concentration of the detection target substance included in the tears becomes a predetermined concentration.

In the present modification example, at least a portion (e.g., a portion to be irradiated with the irradiation light La) of the channel21has a prism shape. At this time, for example, a cross section of at least the portion to be irradiated with the irradiation light La, of the channel21, is shaped like a right-angled triangle. Further, for example, of the channel21, a surface S1corresponding to the hypotenuse of the right-angled triangle is diagonally opposed to a surface on side to be irradiated with the irradiation light La, of the lens section10. Furthermore, for example, of the channel21, a surface S2corresponding to the base of the right-angled triangle is substantially opposed to a surface opposite to the surface on the side to be irradiated with the irradiation light La, of the lens section10.

When the irradiation light La enters the surface S1in the state where the tears with the low concentration of the detection target substance are accumulated in the channel21, for example, as illustrated inFIG. 29, the irradiation light La is refracted by the surface S1and is also refracted by the surface S2. For this reason, the transmitted light Lb at this time exits in a direction different from a direction of an optical axis of the transmitted light Lb in the state where the tears with the high concentration of the detection target substance are accumulated in the channel21(seeFIG. 30). This results in a difference in light receiving position in the light receiving section50, between the state where the tears with the low concentration of the detection target substance are accumulated in the channel21and the state where the tears with the high concentration of the detection target substance are accumulated in the channel21. An amount of this difference varies depending on a magnitude of the refractive index of the tears, which possibly varies depending on the type and the concentration of the component included in the tears. For this reason, in a case where the light receiving section50includes, for example, a CCD (Charge Coupled Device) image sensor, a CMOS (Complementary Metal Oxide Semiconductor) image sensor, or the like, the signal processing section60is enabled to estimate the type and the concentration of the component included in the tears, on the basis of a position of the transmitted light Lb entering the light receiving section50.

In this way, in the present modification example, the type and the concentration of the component included in the tears are estimated, not only from the absorption spectrum of the transmitted light Lb but also from an amount of a positional difference (an offset amount) of the transmitted light Lb. This makes it possible to perform analysis with high accuracy.

Modification Example F

FIG. 31andFIG. 32illustrate a modification example of the channel21of the contact lens1according to the above-described modification example A.FIG. 31illustrates an example of an optical path in a state where tears with a low concentration of a detection target substance are accumulated in the channel21.FIG. 32illustrates an example of an optical path in a state where tears with a high concentration of the detection target substance are accumulated in the channel21. It is to be noted that, as illustrated inFIG. 31andFIG. 32, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10changes depending on the concentration of the detection target substance included in the tears. Further, as illustrated inFIG. 32, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10may become substantially zero when the concentration of the detection target substance included in the tears becomes a predetermined concentration.

In the present modification example, at least a portion (e.g., a portion to be irradiated with the irradiation light La) of the channel21has a prism shape. At this time, for example, a cross section of at least the portion to be irradiated with the irradiation light La, of the channel21, is shaped like a right-angled triangle. Further, for example, of the channel21, the surface S1corresponding to the hypotenuse of the right-angled triangle is diagonally opposed to the surface on the side to be irradiated with the irradiation light La, of the lens section10. Furthermore, for example, of the channel21, the surface S2corresponding to the base of the right-angled triangle is substantially opposed to the surface opposite to the surface on the side to be irradiated with the irradiation light La, of the lens section10.

When the irradiation light La enters the surface S1in the state where the tears with the low concentration of the detection target substance are accumulated in the channel21, for example, as illustrated inFIG. 31, the irradiation light La is refracted by the surface S1and is also refracted by the surface S2. Furthermore, the light refracted and transmitted by the channel21is reflected by the reflection layer22, and refracted by the surfaces S2and S1again, and then exits from the surface on the side irradiated with the irradiation light La, as the reflected light Lc.

The reflected light Lc at this time exits in a direction different from a direction of an optical axis of the reflected light Lc in the state where the tears with the high concentration of the detection target substance are accumulated in the channel21(seeFIG. 32). This results in a difference in light receiving position in the light receiving section50, between the state where the tears with the low concentration of the detection target substance are accumulated in the channel21and the state where the tears with the high concentration of the detection target substance are accumulated in the channel21. An amount of this difference varies depending on the magnitude of the refractive index of the tears, which possibly varies depending on the type and the concentration of the component included in the tears. For this reason, in a case where the light receiving section50includes, for example, a CCD image sensor, a CMOS image sensor, or the like, the signal processing section60is enabled to estimate the type and the concentration of the component included in the tears, on the basis of the position of the transmitted light Lb entering the light receiving section50.

In this way, in the present modification example, the type and the concentration of the component included in the tears are estimated, not only from the absorption spectrum of the transmitted light Lb but also from an amount of a positional difference (an offset amount) of the transmitted light Lb. This makes it possible to perform analysis with high accuracy.

It is to be noted that, in the present modification example, for example, as illustrated inFIG. 33andFIG. 34, the reflection layer22may be formed inside the lens section10. At this time, the reflection layer22may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21. In such a case, the reflection layer22does not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example G

FIG. 35andFIG. 36illustrate a modification example of the channel21of the contact lens1according to the above-described modification example B.FIG. 35illustrates an example of an optical path in a state where tears with a low concentration of a detection target substance are accumulated in the channel21.FIG. 36illustrates an example of an optical path in a state where tears with a high concentration of the detection target substance are accumulated in the channel21. It is to be noted that, as illustrated inFIG. 35andFIG. 36, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10changes depending on the concentration of the detection target substance included in the tears. Further, as illustrated inFIG. 36, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10may become substantially zero when the concentration of the detection target substance included in the tears becomes a predetermined concentration.

In the present modification example, at least a portion (e.g., a portion to be irradiated with the irradiation light La) of the channel21has a prism shape. At this time, for example, a cross section of at least the portion to be irradiated with the irradiation light La, of the channel21, is shaped like a right-angled triangle. Further, for example, of the channel21, the surface S1corresponding to the hypotenuse of the right-angled triangle is diagonally opposed to the surface on the side to be irradiated with the irradiation light La, of the lens section10. Furthermore, for example, of the channel21, the surface S2corresponding to the base of the right-angled triangle is substantially opposed to the surface opposite to the surface on the side to be irradiated with the irradiation light La, of the lens section10.

When the irradiation light La enters the surface S1in the state where the tears with the low concentration of the detection target substance are accumulated in the channel21, for example, as illustrated inFIG. 35, the irradiation light La is diffracted by the diffraction element23, and further refracted by the surfaces S1and S1, and then exits from the surface on the side irradiated with the irradiation light La, as the diffracted-transmitted light Ld.

The diffracted-transmitted light Ld at this time exits in a direction different from a direction of an optical axis of the diffracted-transmitted light Ld in the state where the tears with the high concentration of the detection target substance are accumulated in the channel21(seeFIG. 36). This results in a difference in light receiving position in the light receiving section50, between the state where the tears with the low concentration of the detection target substance are accumulated in the channel21and the state where the tears with the high concentration of the detection target substance are accumulated in the channel21. An amount of this difference varies depending on the magnitude of the refractive index of the tears, which possibly varies depending on the type and the concentration of the component included in the tears. For this reason, in a case where the light receiving section50includes, for example, a CCD image sensor, a CMOS image sensor, or the like, the signal processing section60is enabled to estimate the type and the concentration of the component included in the tears, on the basis of the position of the diffracted-transmitted light Ld entering the light receiving section50.

In this way, in the present modification example, the type and the concentration of the component included in the tears are estimated, not only from the absorption spectrum of the diffracted-transmitted light Ld but also from an amount of a positional difference (an offset amount) of the diffracted-transmitted light Ld. This makes it possible to perform analysis with high accuracy.

It is to be noted that, in the present modification example, for example, as illustrated inFIG. 37andFIG. 38, the diffraction element23may be formed inside the lens section10. At this time, the diffraction element23may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21. In such a case, the diffraction element23does not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example H

FIG. 39andFIG. 40illustrate a modification example of the channel21of the contact lens1according to the above-described modification example C.FIG. 39illustrates an example of an optical path in a state where tears with a low concentration of a detection target substance are accumulated in the channel21.FIG. 40illustrates an example of an optical path in a state where tears with a high concentration of the detection target substance are accumulated in the channel21. It is to be noted that, as illustrated inFIG. 39andFIG. 40, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10changes depending on the concentration of the detection target substance included in the tears. Further, as illustrated inFIG. 40, the difference (the refractive index difference) between the refractive index of the tears and the refractive index of the lens section10may become substantially zero when the concentration of the detection target substance included in the tears becomes a predetermined concentration.

In the present modification example, at least a portion (e.g., a portion to be irradiated with the irradiation light La) of the channel21has a prism shape. At this time, for example, a cross section of at least the portion to be irradiated with the irradiation light La, of the channel21, is shaped like a right-angled triangle. Further, for example, of the channel21, the surface S1corresponding to the hypotenuse of the right-angled triangle is diagonally opposed to the surface on the side to be irradiated with the irradiation light La, of the lens section10. Furthermore, for example, of the channel21, the surface S2corresponding to the base of the right-angled triangle is substantially opposed to the surface opposite to the surface on the side to be irradiated with the irradiation light La, of the lens section10. The reflection layer22and the diffraction element23are disposed to be opposed to each other, with at least the portion having the prism shape of the channel21interposed therebetween.

When the irradiation light La enters the surface S1in the state where the tears with the low concentration of the detection target substance are accumulated in the channel21, for example, as illustrated inFIG. 39, the irradiation light La is diffracted by the diffraction element23, and further refracted by the surfaces S1and S2. Further, the light refracted and transmitted by the channel21is reflected by the reflection layer22and refracted by the surfaces S2and S1again, and then exists from the surface on the side irradiated with the irradiation light La, as the diffracted-reflected light Le.

The diffracted-reflected light Le at this time exits in a direction different from a direction of an optical axis of the diffracted-reflected light Le in the state where the tears with the high concentration of the detection target substance are accumulated in the channel21(seeFIG. 40). This results in a difference in light receiving position in the light receiving section50, between the state where the tears with the low concentration of the detection target substance are accumulated in the channel21and the state where the tears with the high concentration of the detection target substance are accumulated in the channel21. An amount of this difference varies depending on the magnitude of the refractive index of the tears, which possibly varies depending on the type and the concentration of the component included in the tears. For this reason, in a case where the light receiving section50includes, for example, a CCD image sensor, a CMOS image sensor, or the like, the signal processing section60is enabled to estimate the type and the concentration of the component included in the tears, on the basis of the position of the diffracted-reflected light Le entering the light receiving section50.

It is possible to perform measurement of the component of the tears accumulated in the contact lens1according to the present modification example, using, for example, the measurement device2illustrated in each ofFIG. 22,FIG. 25,FIG. 27, andFIG. 28. At this time, the light receiving section50detects the light (the diffracted-reflected light Le) diffracted by the diffraction element23, refracted by the portion having the prism shape of the channel21, transmitted by the tears accumulated in the one or plurality of structure portions20, reflected by the reflection layer22, and refracted by the portion having the prism shape of the channel21again, and further transmitted by the accumulated tears as well as being diffracted by the diffraction element23, of the light (the irradiation light La) emitted toward the tears accumulated in the one or plurality of structure portions20. The light receiving section50outputs the detection signal generated by receiving the diffracted-reflected light Le to the signal processing section60. The signal processing section60analyzes the inputted detection signal, and determines the state of the living body using, for example, the above-described analysis method. It is to be noted that, when using the measurement device2illustrated in each ofFIG. 25,FIG. 27, andFIG. 28, it is possible to measure the component of the tears, in the state where the contact lens1according to the present modification example is attached to the eyeball100.

In this way, in the present modification example, the type and the concentration of the component included in the tears are estimated, not only from the absorption spectrum of the diffracted-reflected light Le but also from an amount of a positional difference (an offset amount) of the diffracted-reflected light Le. This makes it possible to perform analysis with high accuracy.

It is to be noted that, in the present modification example, for example, as illustrated inFIG. 41andFIG. 42, the reflection layer22and the diffraction element23may be formed inside the lens section10. At this time, the reflection layer22may be provided in contact with the surface of the channel21, or may be provided to be a portion of the inner surface of the channel21. In such a case, the reflection layer22and the diffraction element23do not touch the eyeball100, thereby making it possible to reduce the burden on the body further.

Modification Example I

FIG. 43andFIG. 44illustrate a modification example of the structure portion20of the contact lens1according to each of the foregoing embodiment and the modification examples A to H thereof.FIG. 43illustrates a configuration example of a horizontal cross section of the channel21.FIG. 44illustrates a configuration example of a vertical cross section of the channel21.

In the present modification example, the one or plurality of structure portions20includes a suction chamber21C coupled to the channel21(the outlet21B). In other words, the outlet21B is not exposed on the surface of the lens section10. Further, the one or plurality of structure portions20includes a sealing section24that seals an inlet21fof the channel21. The suction chamber21C is filled with gas of pressure lower than atmospheric pressure. Coupling between the suction chamber21C and outside air is blocked by the sealing section24. The sealing section24includes, for example, a material dissolvable by the tears. For this reason, when the contact lens1is attached to the eyeball100, the sealing section24is dissolved by the tears, and the suction chamber21C communicates with the outside air. As a result, the tears are drawn into the suction chamber21C through the channel21, and accumulated in the channel21and the suction chamber21C. It is to be noted that a cover material not to be dissolved by tears may be provided between the sealing section24and the inlet21fThe cover material is detached from the inlet21fby the dissolution of the sealing section24by the tears. It is to be noted that the inlet21A may be exposed on the surface on the side to be in contact with the eyeball100, of the lens section10, or may be exposed on the surface on the side not to be in contact with the eyeball100. The entrance21A is, for example, disposed at a position close to the edge of the lens section10, in the channel21. In other words, the inlet21A is, for example, disposed at a position close to the lacrimal gland when the contact lens1is attached to the eyeball100.

In this way, in the present modification example, the tears are accumulated in the channel21and the suction chamber21C by the dissolution of the sealing section24. This makes it possible to, for example, measure the absorption spectrum of the tears with accuracy. Here, because the light does not pass through a large-absorption region such as skin when the light is emitted toward the tears, it is possible to, for example, measure the absorption spectrum of the tears easily. Further, it is easy to separate noise and a signal of a detection target. Furthermore, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small. It is therefore possible to perform analysis with high accuracy while keeping a burden on a body small.

Modification Example J

FIG. 45illustrates a modification example of the structure portion20of the contact lens1according to the above-described modification example I.FIG. 45illustrates a configuration example of a horizontal cross section of the channel21.

In the present modification example, the one or plurality of structure portions20includes a plurality of storage chambers25coupled to the channel21(the outlet21B). Each of the storage chambers25and the channel21are coupled by a coupling channel25A narrower than the storage chamber25. Coupling positions of the respective coupling channels25A with respect to the channel21vary. Distances of the respective coupling channels25A from the inlet21A are therefore different from each other. Here, the channel21may be subjected to a water-repellent treatment. Further, each of the storage chambers25may include a material (a reaction material26) that develops color or displays fluorescence by enzymatic reaction or chemical reaction with the tears. The reaction material26includes, for example, oxygen, and causes the following reaction with glucose included in the tears. In the following reaction, a quinone pigment with largest absorption at a wavelength of 558 nm is generated. It is possible to detect a glucose concentration by measuring absorption of this quinone pigment at a wavelength of 550 nm.
Glucose+O2+H2O→glucose oxidase→H2O2+gluconic acid 2H2O2+4−AA+DEA→peroxidase→quinone pigment+4H2O

Further, because the coupling positions of the respective coupling channels25A with respect to the channel21vary, a time during which the reaction material26reacts with the tears is different for each of the storage chambers25. This makes it possible to estimate a change with time of the component included in the tears by detecting a reaction state of the reaction material26, for each of the storage chambers25. It is to be noted that a reaction time of the reaction material26in each of the storage chambers25is adjustable by adjusting a negative pressure, etc. of the suction chamber21C.

Further, in a case where each of the coupling channels25A is subjected to the water-repellent treatment, when the negative pressure of the suction chamber21C is released, and an inflow of the tears into the channel21is stopped, the tears collected in the channel21and the tears collected in each of the storage chambers25(a liquid in a state of color development or fluorescence display) are spatially separated from each other by a water-repellent effect of each of the coupling channels25A. This makes it possible to prevent the tears collected in each of the storage chambers25(the liquid in the state of color development or fluorescence display) from flowing into the channel21and thereby mixing with tears collected in the other storage chambers25.

Modification Example J

FIG. 46illustrates a modification example of the glasses4used in the above-described modification example C.FIG. 46illustrates an example in which a medicinal-solution supply device5is provided in the temple42. For example, when the user wears the glasses4, a needle provided in the medicinal-solution supply device5sticks in the user, and the medicinal-solution supply device5supplies the user with, for example, a medicinal solution such as insulin. The measurement device2is enabled to monitor, in real time, an effect of the medicinal solution supplied to the user, by analyzing the component of the tears.

3. Second Embodiment

A contact lens3according to a second embodiment of the present disclosure is described.FIG. 47illustrates an example of a state where the contact lens3is attached to the eyeball100.FIG. 48illustrates an example of a cross-sectional configuration of the contact lens3and the eyeball100. The contact lens3includes the lens section10attachable to the eyeball100, and one or a plurality of structure portions80provided in the lens section10. The one or plurality of structure portions80is a structure that accumulates tears, and further a structure that guides external light to the pupil120or the iris110.

The one or plurality of structure portions80is formed, for example, to avoid the middle of the lens section10. The one or plurality of structure portions80is formed, for example, as illustrated inFIG. 48, to avoid a point opposed to a middle of the pupil120, when the contact lens3is attached to the eyeball100. In the one or plurality of structure portions80, one end is disposed at a position close to an end portion of the lens section10, and another end is disposed at an edge of the pupil120or the iris110, when the contact lens3is attached to the eyeball100. It is to be noted that the one or plurality of structure portions80may be provided only at the middle of the lens section10, or may be provided in a region including the middle of the lens section10. In the one or plurality of structure portions80, one end may be disposed at a position close to the end portion of the lens section10, and another end may be disposed at the middle of the pupil120or the iris110, when the contact lens3is attached to the eyeball100.

The one or plurality of structure portions80includes, for example, a channel81provided inside the lens section10. The channel81has, for example, a cylindrical shape extending in a direction parallel to the surface of the lens10, as illustrated inFIG. 48. A cross-section shape of the channel21is, for example, a rectangular shape, a polygonal shape, a circular shape, or an elliptical shape. It is to be noted that a case where the cross-section shape of the channel21is a rectangular shape is exemplified inFIG. 49andFIG. 50. It is to be noted that, in a case where the lens section10is provided with the plurality of structure portions80(i.e., the plurality of channels81), the plurality of structure portions80(i.e., the plurality of channels81) may be disposed at respective positions opposed to each other with the middle of the lens section10interposed therebetween. For example, in a case where the two structure portions80(i.e., the two channels81) are provided in the lens section10, the two structures portions80(i.e., the two channels81) may be disposed at respective positions opposed to each other with the middle of the lens section10interposed therebetween.

The channel81includes, for example, an opening81A serving as an inlet for the tears, and an opening81B serving as an outlet for the tears, as illustrated inFIG. 48,FIG. 49, andFIG. 50. The opening81A is exposed, for example, on the surface on the side to be in contact with the eyeball100, of the lens section10. The opening81B is exposed, for example, on the surface on the side not to be in contact with the eyeball100, of the lens section10. The opening81A is, for example, disposed at a position close to the edge of the lens section10, in the channel81. It is preferable that, of the channel81, a point (an inflow path) relatively close to the opening81A have, for example, a width that makes it possible to draw the tears in by the capillary phenomenon. It is preferable that, of the channel81, a point (a discharge path) relatively close to the opening81B have, for example, a width wider than that of the point relatively close to the opening81A, of the channel81. It is to be noted that, of the channel81, the point (the discharge path) relatively close to the opening81B may have a width equal to that of the point relatively close to the opening81A, of the channel81. Of the channel81, the width of the point relatively close to the opening81B has a distance that, for example, makes it difficult to cause the capillary phenomenon. A portion or whole of the channel81may be subjected to, for example, a hydrophilic treatment to make the tears flow easily.

The one or plurality of structure portions80includes a reaction material82being in contact with an inner surface of the channel81. The reaction material82is provided as a thin layer on the inner surface of the channel81to the extent of not blocking the channel81. The reaction material82includes, for example, a material that develops color or displays fluorescence by enzymatic reaction or chemical reaction with the tears. The reaction material82includes, for example, oxygen, and causes the following reaction with glucose included in the tears. In the following reaction, a quinone pigment with largest absorption at a wavelength of 558 nm is generated. At this time, a glucose concentration is detected by color of external light L transmitted by a solution in which this quinone pigment is dissolved. It is to be noted that the reaction material82is not limited to the above-described material, and is allowed to include a material appropriate for a detection target. The reaction material82may include other material, and may include, for example, a boronic acid. Examples of the boronic acid include phenylboronic acid, anthrylboronic acid, aromatic boronic acid, arylboronic acid, ArB(OH)2, etc.
Glucose+O2+H2O→glucose oxidase→H2O2+gluconic acid 2H2O2+4−AA+DEA→peroxidase→quinone pigment+4H2O

The one or plurality of structure portions80includes a reflecting mirror81C that guides the external light L entering through the opening81B to inside of the channel81, and a reflecting mirror81D that reflects the external light L propagating through the inside of the channel81to the pupil120or the iris110through the opening81A. The reflecting mirror81C is disposed to cause multiple reflection of the light reflected by the reflecting mirror81C, on the inner surface of the channel81. It is to be noted that a case where the reflecting mirror81C is disposed to cause the multiple reflection of the light reflected by the reflecting mirror81C on upper and lower surfaces of the inner surface of the channel81is exemplified inFIG. 49. Further, a case where the reflecting mirror81C is disposed to cause the multiple reflection of the light reflected by the reflecting mirror81C on right and left surfaces of the inner surface of the channel81is exemplified inFIG. 50.

It is to be noted that, for example, as illustratedFIG. 51, a diffraction element83that guides the external light L to the inside of the channel81may be provided in place of the reflecting mirror81C. Further, for example, as illustrated inFIG. 51, a diffraction element84that guides the external light L propagating through the inside of the channel81to the pupil120or the iris110through the opening81A may be provided in place of the reflecting mirror81D. The diffraction element83is configured to allow refraction of the external light L entering through the opening81B in a predetermined direction in the inside of the channel81, and includes, for example, a holo-graphic optical element (HOE). The diffraction element84is configured to allow refraction of the light propagating through the inside of the channel81in a direction to the opening81A, and includes, for example, a holo-graphic optical element (HOE).

In this way, by causing the multiple reflection in the inside of the channel81, it is possible to increase a propagating distance of the external light L propagating through the inside of the channel81, as compared with a case where the external light L is perpendicularly transmitted by the channel81. For example, suppose the channel81has a height (a thickness) of 0.1 mm, and a length of 4 mm. At this time, in a case where the external light L is perpendicularly transmitted by the channel81, a distance in which the external light L passes through the inside of the channel81is only 0.1 mm. In contrast, in a case where the external light L propagates through the inside of the channel81at an internal reflection of 45 degrees, the distance in which the external light L passes through the inside of the channel81is about 5.6 mm. This makes it possible to increase a proportion (an absorption factor) of the external light L to be absorbed by a light absorption material generated by the reaction between the tears and the reaction material82.

Here, an intensity of light propagating through inside of a dilute solution in which a light absorption material is dissolved is proportional to a concentration of the light absorption material included in the dilute solution and a distance in which the light passes through the inside of the dilute solution, from the Lambert-Beer's law. For this reason, as the channel81is longer, an amount of light absorption of the external light L by the solution in which the light absorption material is dissolved, i.e., a degree of a change in color of the external light L transmitted by the channel81, is larger. For example, suppose the channel81has a height (a thickness) of 0.1 mm, and a length of 4 mm. Further, suppose the reaction material82includes a glucose E reagent. At this time, in the case where the external light L is perpendicularly transmitted by the channel81, a proportion (a transmittance) of a component of a wavelength of 505 nm included in the external light L transmitted by the channel81is 99.99959. In this case, visually recognizing a change in the color of the external light L transmitted by the channel81is difficult. In contrast, in the case where the external light L propagates through the inside of the channel81at the internal reflection of 45 degrees, the proportion (the transmittance) of the component of the wavelength of 505 nm included in the external light L transmitted by the channel81is 82.4%. If the transmittance falls to this extent, it is possible to easily perform visual recognition of a change in the color of the external light L transmitted by the channel81. In other words, in this case, it is possible to discriminate a change in blood sugar level by viewing the change.

It is to be noted that, in a case where the reaction material82is a material or in a form that does not dissolve in the tears, as the number of times the external light L is reflected by a surface of the reaction material82within the channel81is larger, the amount of light absorption of the external light L by the reaction material82, i.e., the degree of a change in the color of the external light L transmitted by the channel81, is larger. At this time, it is possible to lower a proportion (a transmittance) of a component of a predetermined wavelength included in the external light L transmitted by the channel81to the extent that it is possible to easily perform visual recognition of a change in the color of the external light L, as described above. In other words, in this case as well, it is possible to discriminate a change in blood sugar level by viewing the change.

Next, an example of a judgement procedure for a state of a living body using the contact lens3is described.FIG. 52illustrates an example of the judgement procedure for the state of the living body using the contact lens3. First, the user attaches the contact lens3to the eyeball100of the user (step S301). Then, the tears are accumulated in the one or plurality of structure portions80(the channel81) provided in the contact lens3by utilizing, for example, the capillary phenomenon.

At this time, the reaction material82reacts with the tears (step S302). As a result, the light absorption material is generated, and the channel81is filled with the dilute solution in which the light absorption material is dissolved in the tears. Here, the concentration of the light absorption material included in the tears changes depending on an amount of the component reacting with the reaction material82, included in the tears. In a case where the reaction material82includes the glucose E reagent, for example, a quinone pigment is generated by the reaction between the reaction material82and the tears, and the channel81is filled with a dilute solution in which the quinone pigment is dissolved in the tears.

Next, the user observes the light outputted from the one or plurality of structure portions80(the channel81) provided in the contact lens3, and determines the state of the living body on the basis of the color of the light (step S303). At this time, when the external light L enters the one or plurality of structure portions80(the channel81), the external light L is absorbed by the light absorption material included in the above-described dilute solution. Here, the amount of light absorption of the external light L by the dilute solution in which the light absorption material is dissolved, i.e., the degree of a change in the color of the external light L transmitted by the channel81, is proportional to the concentration of the light absorption material included in the dilute solution and the distance in which the external light L passes through the inside of the dilute solution. This enables the user to determine the state of the living body on the basis of the color of the light outputted from the one or plurality of structure portions80(the channel81) provided in the contact lens3.

In the present embodiment, the one or plurality of channels81is provided with a reflecting mirror81B or the diffraction element83that guides the external light L to the inside of the channel81, and a reflecting mirror81A or the diffraction element84that guides the external light L propagating through the inside of the channel81to the pupil120or the iris110, and is further provided with the reaction material82within the channel81. This enables the user to judge the state of the living body simply and in real time by observing the color of the light outputted from the one or plurality of structure portions80(the channel81) while the contact lens1remains attached to the eyeball100. As a result, for example, it is possible for the user to judge the state of the living body simply and in real time even while the user is carrying out any activity, and thus, in a case where the user suffers from diabetes, the user is enabled to judge instantly whether it is necessary to inject insulin now. Further, because an electrode is unnecessary, issues such as long-term stability and heat resistance attributable to an electrode, and responsiveness to a substance other than a detection target, are not present. Moreover, because this is of the non-invasive type, a burden on a body is small. It is therefore possible to perform analysis with high accuracy while keeping a burden on a body small.

4. Modification Examples of Second Embodiment

In the second embodiment, for example, as illustrated inFIG. 53, the contact lens3may include a color index90. The color index90is a color sample intended for comparison with the color of the light outputted from the one or plurality of structure portions20(the channel81) provided in the contact lens3. When the contact lens3is attached to the eyeball100, the color index90is provided, for example, in proximity to the edge of the pupil120or the iris110. In such a case, the user is enabled to judge the state of the living body instantly and accurately by comparing the color of the light outputted from the one or plurality of structure portions80(the channel81) and the color index90.

It is to be noted that, for example, as illustrated inFIG. 54(A)andFIG. 54(B), the color index90may be disposed to be adjacent to the structure portion80(in particular, the opening81B). It is to be noted that a plane configuration of the one or plurality of structure portions80and the color index90is exemplified inFIG. 54(A). Further, a cross-sectional configuration at a line A-A inFIG. 54(A)is exemplified inFIG. 54(B). In such a case, the user is enabled to perform the comparison between the color of the light outputted from the opening81B and the color index90more accurately.

Further, for example, as illustrated inFIG. 54(B), the color index90may be provided in contact with a surface3A on the eyeball100side, of the lens10. In such a case, it is possible to prevent the color index90from being changed in color by the external light L when the user visually recognizes the color index90. As a result, the user is enabled to perform the comparison between the color of the light outputted from the structure portion80(the channel81) and the color index90more accurately.

It is to be noted that, as illustrated inFIG. 55, the plurality of structure portions80(in particular, the opening81B) and the plurality of color indexes90may be disposed to be alternately aligned in a predetermined direction. It is to be noted that a plane configuration of the plurality of structure portions80and the plurality of color indexes90is exemplified inFIG. 55. In such a case, the user is enabled to perform the comparison between the color of the light outputted from the opening81B and the color index90more accurately.

Further, as illustrated inFIG. 56(A) andFIG. 56(B), in a case where the one structure portion80is formed to have a wide width, the plurality of color indexes90may be disposed to block a portion of the opening81B. It is to be noted that a plane configuration of the one structure portion80and the plurality of color indexes90is exemplified inFIG. 56(A). Furthermore, a cross-sectional configuration at a line A-A inFIG. 56(A) is exemplified inFIG. 56(B). In such a case, the user is enabled to perform the comparison between the color of the light outputted from the opening81B and the color index90more accurately.

Further, as illustrated inFIG. 57, in a case where the plurality of structure portions80(in particular, the opening81B) and the plurality of color indexes90are disposed to be alternately aligned in a predetermined direction, each of the color indexes90may extend in an extending direction of the structure portion80. In such a case, the user is enabled to visually recognize each of the color indexes90clearly, and thus is enabled to perform the comparison between the color of the light outputted from the opening81B and the color index90more accurately.

Further, in the second embodiment, for example, as illustrated inFIG. 58, the one or plurality of structure portions80may include a sealing layer85that seals the opening81B, and a sealing layer86that seals the opening81A. The sealing sections85and86each include, for example, a material dissolvable by the tears. For this reason, when the contact lens3is attached to the eyeball100, the sealing sections85and86are dissolved by the tears, and the channel81communicates with the outside air. As a result, the tears are drawn into the channel81. Here, in a case where the contact lens3is provided with the plurality of structure portions80such as those illustrated inFIG. 54, a dissolution rate of the sealing sections85and86may be different for each of the structure portions80. In such a case, a time during which the reaction material82reacts with the tears is different for each of the structure portions80. This makes it possible to estimate a change with time of the state of the living body by observing the color of the light outputted from the structure portion80, for each of the structure portions80.

Although the present disclosure has been described above referring to the embodiments and modification examples, the present disclosure is not limited thereto, and may be modified in a variety of ways.

For example, the glasses4used in the above-described modification example C or the above-described modification example J may include an element (e.g., a gyro element) that detects a posture of a person. The signal processing device60is enabled to evaluate the detection signal obtained from the light receiving section50, on the basis of information obtained from the element that detects the posture of the person.

Further, for example, in the foregoing embodiments and the modification examples thereof, in a case where an evaluation result obtained from the light receiving section50matches with a predetermined state, the signal processing device60may perform display and/or sound output for an alert.

It is to be noted that the effects described in the present specification are merely examples. The effects of the present disclosure are not limited to those described in the present specification. The present disclosure may include effects other than those described in the present specification.

Further, for example, the present disclosure may have the following configurations.

A contact lens including:

a lens section attachable to an eyeball; and

one or a plurality of structure portions intended to accumulate tears.

The contact lens according to (1), in which the one or plurality of structure portions is formed to avoid a middle of the lens section.

The contact lens according to (1) or (2), in which the one or plurality of structure portions includes a channel provided inside the lens section.

The contact lens according to (3), in which the channel includes an inflow path enabled to draw tears in by a capillary phenomenon.

The contact lens according to (4), in which the channel includes a discharge path having a width wider than a width of the inflow path.

The contact lens according to (4) or (5), in which an entrance of the inflow path is disposed at a position close to an edge of the lens section, in the channel.

The contact lens according to any one of (3) to (6), in which the one or plurality of structure portions further includes a sealing section that includes a material dissolvable by tears and seals an inlet of the channel.

The contact lens according to (7), in which the one or plurality of structure portions further includes a suction chamber coupled to the channel.

The contact lens according to (8), in which the one or plurality of structure portions further includes a plurality of storage chambers that is coupled to the channel and stores tears.

The contact lens according to (9), in which the channel is subjected to a water-repellent treatment.

The contact lens according to (10), in which each of the storage chambers includes a material that develops color or displays fluorescence by enzymatic reaction or chemical reaction with tears.

The contact lens according to any one of (3) to (11), in which the plurality of structure portions is disposed at respective positions opposed to each other with a middle of the lens section interposed therebetween.

The contact lens according to any one of (3) to (12), in which the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the channel in a thickness direction of the lens section.

The contact lens according to (13), in which the one or plurality of structure portions further includes a reflection layer disposed to be opposed to the channel in the thickness direction of the lens section.

The contact lens according to any one of (3) to (12), in which

at least a portion of the channel has a prism shape, and

the one or plurality of structure portions further includes a reflection layer and a diffraction element disposed to be opposed to each other with at least the portion having the prism shape of the channel interposed therebetween.

The contact lens according to any one of (3) to (12), in which the one or plurality of structure portions further includes a reflection layer disposed to be opposed to the channel in a thickness direction of the lens section.

A detection method including:

emitting light toward tears accumulated in one or a plurality of structure portions in a contact lens that includes a lens section attachable to an eyeball, and the one or plurality of structure portions intended to accumulate tears; and

detecting, through the tears accumulated in the one or plurality of structure portions, transmitted light transmitted by the contact lens, reflected light reflected by the contact lens, diffracted-transmitted light diffracted and transmitted by the contact lens, or diffracted-reflected light diffracted and reflected by the contact lens, of the light emitted toward the tears accumulated in the one or plurality of structure portions.

The detection method according to (17), in which

the one or plurality of structure portions further includes a reflection layer disposed to be opposed to the channel in a thickness direction of the lens section, and

the measurement method further includes detecting the reflected light transmitted by the tears accumulated in the one or plurality of structure portions, and reflected by the reflection layer, of the light emitted toward the tears accumulated in the one or plurality of structure portions.

The detection method according to (17), in which

the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the channel in a thickness direction of the lens section, and

the measurement method further includes detecting the diffracted-transmitted light diffracted by the diffraction element, and transmitted by the tears accumulated in the one or plurality of structure portions, of the light emitted toward the tears accumulated in the one or plurality of structure portions.

The detection method according to (17), in which

the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the channel in a thickness direction of the lens section, and a reflection layer disposed to be opposed to the diffraction element with the channel interposed therebetween,

of the channel, at least a portion opposed to the diffraction element has a prism shape, and

the measurement method further includes detecting the diffracted-reflected light diffracted by the diffraction element, refracted by the portion having the prism shape of the channel, transmitted by the tears accumulated in the one or plurality of structure portions, and reflected by the reflection layer, of the light emitted toward the tears accumulated in the one or plurality of structure portions.

The contact lens according to (6), in which

the entrance of the inflow path and an exit of the discharge path are disposed at respective positions that have left-right symmetry with respect to a middle of the lens section, and

the entrance and the exit are configured to have the entrance be disposed at a position relatively close to a lacrimal gland as compared with the exit, in the structure portion relatively close to the lacrimal gland when the contact lens is attached to the eyeball.

The contact lens according to (13), in which the diffraction element is provided inside the lens section.

The contact lens according to (14), in which the reflection layer is provided inside the lens section.

The contact lens according to (3), in which at least a portion of the channel has a prism shape.

The contact lens according to (24), in which the one or plurality of structure portions further includes a reflection layer disposed to be opposed to the portion having the prism shape of the channel in a thickness direction of the lens section.

The contact lens according to (24), in which the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the portion having the prism shape of the channel in a thickness direction of the lens section.

The contact lens according to (25), in which the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the portion having the prism shape of the channel in the thickness direction of the lens section.

The detection method according to (17), in which the one or plurality of structure portions further includes a diffraction element disposed to be opposed to the channel in a thickness direction of the lens section, and a reflection layer disposed to be opposed to the diffraction element with the channel interposed therebetween, and

the measurement method further includes detecting the diffracted-reflected light diffracted by the diffraction element, transmitted by the tears accumulated in the one or plurality of structure portions, and reflected by the reflection layer, of the light emitted toward the tears accumulated in the one or plurality of structure portions.

The detection method according to (17), in which

the diffraction element is disposed at a position farther from the eyeball than the channel is when the contact lens is attached to the eyeball,

the reflection layer is disposed at a position closer to the eyeball than the channel is when the contact lens is attached to the eyeball, and

the measurement method further includes detecting the diffracted-reflected light diffracted by the diffraction element, transmitted by the tears accumulated in the one or plurality of structure portions, and reflected by the reflection layer, of the light emitted toward the tears accumulated in the one or plurality of structure portions, in a state where the contact lens is attached to the eyeball.

The detection method according to (17), in which in the measurement method, an absorption spectrum of tears is derived on a basis of a detection signal obtained by detecting the transmitted light, the reflected light, the diffracted-transmitted light, or the diffracted-reflected light, and a type and a concentration of a component included in the tears is estimated from the derived absorption spectrum.

The contact lens according to any one of (1) to (6), in which the one or plurality of structure portions further includes

a first optical element that guides external light to inside of the channel,

a second optical element that guides the external light propagating through the inside of the channel to a pupil or an iris, and

a reaction material provided in the inside of the channel, the reaction material developing color or displaying fluorescence by enzymatic reaction or chemical reaction with tears.

This application claims the benefit of Japanese Priority Patent Application JP2017-150559 filed with the Japan Patent Office on Aug. 3, 2017, the entire contents of which are incorporated herein by reference.