EYE-PROTECTING MEANS

Abstract: An eye-protecting means comprising a dish-shaped article (1) of transparent inert material adapted for being removably arranged behind the eye-lids (12) in contact with the eye ball (7), and having sufficiently large dimensions to cover the cornea (11) as well as a considerable portion of the white of the eye (8). Is is meant for protection of the human eye against harmful gases and other injurious matter.

Description: An eye-protecting means of simple constructing , which causes little hindrance to the wearer and which can be used in all those places where there is a risk of injurious matter acting onto the eye . Protecting hoods and safety glasses for protec¬ tion of the human eye against injurious effects such as radiation , metal splinters and the like are already known . While such devices usually provide a good protection , they also have certain disadvantages such as a bulky construction restriction of the visual field , hindrance to the wearer and/or a risk of loss during use. In the case of protection against harmful gases , tightly closing safety glasses or a gas mask having built-in glasses are mostly used but the hindrance to the wearer is strongly increased thereby and condensation moisture may easily be deposited onto the glasses . The invention has for its object to remove the aforesaid problems and to provide an eye-protecting means which gives efficient protection against injurious matter and especially against harmful gases at one hand, and which at the other hand is of simple construction , easy to arrange and causing little hindrance during use. To this end , the invention provides an eye- protecting means which is characterised by a dish-shaped article of transparent inert material , adapted for being removably arranged behind the eye lids in contact with the eye ball , and having sufficiently large dimensions to * cover the cornea as well as a considerable portion of the white of the eye. „ Thanks to this eye-protecting means , the object of the invention may be well achieved. The dish-shaped article which has been adapted to the shape of the eye can be easily arranged in its place and will provide then efficient protection against injurious matter and especially against gases , because it covers a major portion of the eye ball. It remains in position during use , thanks to the eye lids , and may be easily removed after use . The view is not hindered and the visual field will not be _ O PI ~~ restricted with this eye-protecting means , while little hindrance is caused to the wearer and no deposition of condensation moisture onto the inner side of the article will occur. Moreover, there is a possibility now that particles of dust and dirt which hit the eye-protecting means from the exterior during use , are wiped away with the aid of the eye lids . The eye-protecting means according to the invention is in the first place applicable for use against the action of harmful gases such as tear gas , smoke and mist, but it may also be used in many other cases. These cases of utilisation , as well as further characteristics and advantages of the invented eye-protecting means will appear from the description to follow. rt should be noted that the invented eye- protecting means has a certain similarity with contact lenses . However, by its shape , a normal contact lens has always a lens function for correction of the sight , and its dimensions are such that only the cornea will be covered. Contrary thereto, the invented eye-protecting means does not necessarily have a lens function (although that may be incorporated in some case) and- its dimensions are larger in such a way that not only the cornea but a considerable portion of the white of the eye is covered as well. Therefore , there is a clear distinction in terms of dimensions and. function. The invention is illustrated further by means of the drawing which shows a pair of embodiments by way of example. Fig. l shows a first embodiment of the invented eye -protectin _ g means , in cross-section and at an enlarged scale, Figs τ „ 2 and 3 are a vertical cross-section and a front view of the human eye, respectively, with the eye— protecting means of fig. 1 arranged in position. Fig. 4 is a similar front view as fig. 3 but this time showing a second embodiment of the eye-protecting means of the invention. Λ Figs .5 and 6 are cross— sections of the eye- protecting means of fig. 4 , said cross-sections being taken perpendicularly to the longitudinal axis and along the longitudinal axis of the eye-protecting means , respectively . The embodiment of fig. 1 , which is preferred at the moment , comprises a dish-shaped article 1 of transparent inert material having a circular peripheral edge 2. Shape en dimensions have been selected such that the article may easily be arranged behind the eye lids of a human eye , thereby contacting the eye ball. . This dish-shaped article has a central portion 3 , having a radius of curvature adapted to the curvature radius of the cornea of a human eye , and further a peripheral . ' .portion 4 extending until the peripheral edge 2 and having a gradually increasing radius of curvature. The transition between both portions is . located at 5. The article is bevelled from a location 6 until the peripheral edge 2. Fig. 2 first shows a cross-section through the human eye. The eye ball 7 and many constituents thereof are visible , such as the white of the eye or sclera 8 and the lens 10 which is held in position by ciliary muεicles 9. The transparent cornea 11 which has a higher curvature than the rest of the eye ball 7 is in front- of the eye ball and spaced thereof. This cornea may be covered temporarily by the eye lids 12 , 12. In fig. 2 , the eye-protecting means of fig. 1 has already been arranged in position behind the eye lids , this eye-protecting means thereby contacting the eye ball 7. Only the peripheral portions are somewhat spaced from the eye ball . Fig. 3 shows a front view of the same eye. Visible are the eye lids 12 , 12 as well as some parts of the eye ball such as the white of the eye 8 , the lens 13 and the pupil 14. Both latter parts carry the cornea (not visible) . Further, the eye-protecting means of fig. 1 is present and its circular peripheral edge 2 can be seen. It appears from figs . 2 and 3 that the eye- protecting means 1 during its use will not only cover the the cornea 11 but a considerable portion of the white of the eye (sclera) 8 outside the cornea as well. This means that the eye is protected efficiently during use against the action of exogenic injurious matter and especially harmful gases. Moreover, it appears from fig. 2 that a certain spare room 15 is remaining behind the eye lids, thus allowing an easy insertion and removal of the eye- protection means. Figs. 4 to 6 relate to a second embodiment of the invented eye-protecting means , said embodiment distinguishing itself from the first by the fact that the peripheral edge is not circular but elliptic. Fig. 4 shows again a human eye in front view, having eye lids 12 , 12 , white of the eye 8 , a lens 13 and a pupil 14. An eye-protecting means according to ..the second embodiment has been arranged in this eye but only its elliptic peripheral edge 17 is visible. Thanks to this elliptic peripheral edge, a larger portion of the white of the eye 8 is covered by the eye-protecting" means during its use. Figs. 5 and 6 are cross-sections of the eye- protecting means used in fig. 4, the cross-section of fig; 5 being taken across the longitudinal axis and the crσssr section of fig. 6 being taken along the longitudinal ' axis of the ellips. According to fig- 5, this eye-protecting means again comprises a dish-shaped article 16 having a central portion 18 and peripheral portions 19,20 which are bevelled from.location 21. The curvature radius R of the central portion 18 has been adapted to that of the human cornea while the curvature radius of the peripheral portions 19 ,2 _>0 ' is gradually increasing. A similar view is seen in the cross-section of fig. 6 , viz . a central portion 18 and peripheral portions 22 ,22 , but the peri¬ pheral portions are much larger than in fig. 5 so as to create a more flattened appearance. As an extra provision , the peripheral portion 20 in fig. 5 has been made somewhat thicker than portion 19 so as to create a weight at that location which may serve to keep the eye-protection means better in its position. Both embodiments of the drawing are of simple construction and easy to arrange and to remove while no restriction of the visual fiels, no hindrance " to the wearer and no risk of loss will be involved during their utilisation. Moreover, they provide an efficient protection against injurious matter, especially harmful gases, thanks to the fact that the cornea as well as a considerable portion of the white of the eye are masked. Some further reflections on the shape and dimensions of the eye-protecting means as used will follow now. In the embodiment of fig. 1, the diameter D of the peripheral edge 2 should be larger than in a normal contact lens because the eye-protecting means should cover not only the cornea but also a considerable portion of the white of the eye. Ofcourse, the upper limit of the • diameter D is restricted by the requirement that the eye- protecting means can be easily arranged behind the eye¬ lids. In view of the variable dimensions of the human eye ball, D may vary from 15.3 mm for large eyes to 14.8 mm for small eyes. The thickness of the dish-shaped article 1 may be relatively small in view of good comfort but should be sufficient to maintain a good strength of the material. In general, * this thickness is constant about the whole article, with the exception of the bevelled portions, since the article is meant as eye-protecting means and not as a lens. If desired, and in special cases, a lens function for correction of " Sight may be added by variation of thickness. In general, the shape of the dish-shaped article 1 is such that a good adaptation to the shape of the human eye is obtained while easy insertion and removal of the article remains possible. Thus, the central portion 3 is adapted to the shape and dimensions of the human cornea while the peripheral portion has a gradually increasing curvature radius for adaptation to the shape of the white of the eye and in view of an easy removal. The transition - l)__- L -- rι P at 5 should be so gradual that the user does not perceive a sharp boundary line. Similar remarks can be made to the embodiment of figs. 4 to 6. This embodiment has a variable diameter 5 indeed, but the same requirements as to the diameter D in fig. 1 may be applied to the diameter Dl of fig. 5, and the diameter D2 of fig. 6 may be considerably larger. Again, the central portion 18 is adapted to the shape and dimensions of the cornea and the peripheral portions 19,20, 10 22,22 have a gradually increasing radius of curvature. In a practical example, the embodiment of fig. 1 may comprise a dish-shaped article having a peripheral diameter of 15.3 mm, the central portion 3 thereof extending to a diameter of 11.8 mm and having a curvature radius 15 of 9.8 mm. The radius of curvature is gradually increasing from 9.8 mm to 12.5 mm in the peripheral portion 4. The article has a thickness of 0.17 mm and is bevelled near the peripheral edge along a distance of 1-2 mm. In another practical example, relating to the 2.0 embodiment of figs. 4 to 6, the eye-protecting means comprises a dish—shaped article of elliptic circumference, having a diameter of 18 mm along its longitudinal axis and of 15.3 mm across that axis. The central portion 18 extending to a diameter 25 of 11.8 mrahas a radius of curvature of 9.8 mm and this curvature radius is gradually increasing to 12.25 mm in the peripheral portions 19,20.and to higher values in the peripheral portions 22,22- Again, the article has a thickness of 0.17 mm and is bevelled near its periphery 30 along a distance of 1.2 mm. A thickening serving as a weight is pre __sent in the portion 20. The eye-protecting means of the invention may be manufactured from the same material as conventional contact lenses , that is e.g. from glass or synthetic resin. 35 In the case of synthetic resins , a selection may be made between hard materials such as e. g. polymethyl methacrylate , and soft materials such as polyhydroxye hyl methacrylate. Further, these soft materials may have a variable water content, for instance 39% or 85% of water. Preferably, the material as used is permeable to oxygen so that the oxygen economy of the eye is not endangered. However, the pores in the material should not be larger than about 40 8. so as to prevent harmful gases from penetrating into the eye. Ofcourse, many variations are possible on the embodiments described. Thus, the embodiment of fig. 1 need not necessarily be aspheriσ but it may be spheric (with a constant curvature radius) as well. The possibility of a variable thickness of material in view of the incorporation of a lens function has already been mentioned. An additional advantage is that the eye-protecting means may be manufactured easily in mass production and may be disposed of, if desired, after use. The invented eye-protecting means may be used for protection against harmful gases such as tear gas, smoke, mist, haze, fire-extinguishing powder and the like, but also as a protection against dust, sand, grit, dirt, acids and caustics. This means that it- may be used by policemen, military personel, members of the fire brigade, but also by workers in the petrochemical industry and in laboratories. In cases where the use of safety glasses has been prescribed by law, this eye-protecting means may be used in stead of of in combination with such safety glasses.

Claims: CLAIMS 1. Eye-protecting means , characterised by a dish-shaped article of transparent inert material adapted for being removably arranged behind the eye lids in contact with the eye ball and having sufficiently large dimensions to cover the cornea as well as a substantial portion of the white of the eye. 2. The eye-protecting means of claim 1 , characterised in that said dish-shaped article has a circular peripheral edge. 3. The eye-protecting means of claim 2 , characterised in that said article has a diameter of about 15.3 mm at its periphery. 4. The eye-protecting means of claim 1 , characterised in that said dish-shaped articlehas a elliptic peripheral edge. 5. The eye-protecting means of claim 4 , characterised in that said article has a diameter of about 18 mm along its longitudinal axis and a diameter of about 15. 3 mm across its longitudinal axis . 6. The eye— protecting means of claims 1— 5 ,. characterised in that" said article is- aspheric .and comprises a central portion having a curvature radius accommodated to the cornea, and a peripheral portion having a gradually increasing curvature radius. 7. The eye— protecting means of claims 1-6 , characterised in * that said article carries a weight at a location near to its edge .

Inventors: VAN DER LINDEN JAN WILLEM, VISSER RIENTS, VAN DER LINDEN, JAN, WILLEM, VISSER, RIENTS
Applicants: EYE P INTERNATIONAL B V, EYE-P INTERNATIONAL B.V.
Application year: 1983
Main classification: A61F9
IPC codes: A61F9, G02C7