Chapter 2: The First Steps in Vision: From Light to Neutral Signals Flashcards
to take up something— such as light, noise, or energy— and not transmit it at all
absorb
to redirect something that strikes a surface— especially light, sound, or heat— usually back toward its point of origin
reflect
to alter the course of a wave of energy that passes into something from another medium, as water does to light entering it from the air
refract
the watery fluid in the anterior chamber of the eye
aqueous humor
the structure inside the eye that enables the changing of focus
lens
the dark, circular opening at the center of the iris in the eye, where light enters the eye
pupil
the colored part of the eye, consisting of a muscular diaphragm surrounding the pupil and regulating the light entering the eye by expanding and contracting the pupil
iris
the transparent (gel-like) fluid that fills the vitreous chamber in the posterior part of the eye
vitreous humor
a light-sensitive membrane in the back of the eye that contains photoreceptors and other cell types, that transduce light into electrochemical signals and transmits them to the brain through the optic nerve (contains rods and cones)
retina
literally “old sight”. The age-related loss of accommodation, which makes it difficult to focus on near objects
presbyopia
nearsightedness, a common condition in which light entering the eye is focused in front of the retina and distant objects cannot be seen sharply
myopia
a photoreceptor specialized for night vision
rod
a photoreceptor specialized for daylight vision, fine visual acuity, and color
cone
a small pit located near the center of the macula and containing the highest concentration of cones and no rods. It is the portion of the retina that produces the highest visual acuity and serves as the point of fixation
fovea
antagonistic neural interaction between adjacent regions of the retina
lateral inhibition
