### definite unit:

Rod
* All rods contain amorphous and graphite carbon.
* absorb light in low light situations, and are therefore essential to night vision.
* are among the most metabolically active cells in the body
  - better for night vision because they are sensitive to small quantities of light
  - blind to red light
  - cells which help the brain interpret images seen in low light
  - common in the medical profession
  - cylindrical or cigar shaped objects that have been discovered appearing in the skies
  - extremely sensitive to light and are used for night vision
  - far more sensitive than cones, giving night vision with the pupils wide open
* are for night vision , and sense shades of grey
  - sensing motion and work best in low light levels
  - generally medium to large weight
  - highly sensitive photoreceptors and are used for vision under dark-dim conditions at night
  - important for seeing in low light
  - larger in size than cones
  - microscopic sence organs in the retina of the eye that are sensetive to dim light
* are more light sensitive and function in low light intensity or in the dark
  - than cones and are responsible for night vision
  - near the periphery of the retina
  - numerous than cones in the periphery of the retina
  - sensitive than cones and are better for low light vision
  - part of miles
  - photoreceptors in the retina that respond to dim light
* are responsible for color vision
  - colorless vision in dim light
  - dim-light and peripheral vision and are more sensitive to light than cones
  - magnifying light impulses
  - scotopic vision
  - vision in dim light through rhodopsin
  - sensitive in poor light and are developed best in nocturnal animals
* are sensitive to color and cones are sensitive in low light
* are sensitive to dim light and black and white
  - light, while cones work in bright light
  - light levels and cones are sensitive to colour
  - weak light and bleached out by strong light
  - sensors that detect brightness and darkness, and cones are sensors that detect colors
  - solid fiberglass
  - specialized for vision in dim light and cones mediate vision in bright light
* are the receptors for geryscale and low level light
  - that the eye uses for night time viewing and sudden movement
  - used mostly for night vision, the cones becoming quite blind
* are very sensitive to dim light, but relatively useless for color vision
  - unresponsive to red light
* become more active as dark adaptation proceeds.
* can bring crop residue back up to the soil surface to provide more soil protection
  - function with much less light than cones, so they take over when the light dims
* can respond to dim light, and thus make night vision possible
  - light but also to pressure
* can vary as long as they have strong guides that resist abrasion
  - have sufficient guides to resist abrasion
* cancel cones in flicker.
* contain the light-absorbing molecule called rhodopsin
  - purple pigment rhodopsin
* convey the ability to see at night, under conditions of very dim illumination.
* cover the majority of the periphery and serve for vision in poor light and spacial awareness.
* dominate at low luminance levels
  - night while cones dominate during the day
* follow hand motion closely and can stop instantly when hand stops.
* function at low light levels c
  - better in dim light, while cones are used for color vision and require bright light
  - in low light or at night
* have an outer segment attached to the cell body by a modified cilium
  - no color perception ability
* help in night vision.
* includes fts
  - yards
* is an implement
  - precision made in brass
  - the god of fertility and light
* mediate black and white vision and are used mainly at night.
* plays a musical instrument.
* primarily influence visual perception when the light intensity is low or dim.
* produce a black and white response, which is actually a reaction to variations in luminance.
* provide night vision and detect motion.
* register shapes and respond to low levels of light.
  - various colours, but give a sensation only of black, grey or white
* see black and white, and cones see in color.
* sense light and dark, no color.
* show a tendency to cluster under the sarcolemma and around nuclei.
* support and a weapon.
* symbolize the diverse tribes who find strength only when bound together for the common good.
* trigger light adaptive retinomotor movements in all spectral cone types of a teleost fish.
* work best when light is dim, like in the late evening.