Vision 1 Flashcards
(21 cards)
What is the main function of eye?
capture light at front and project detailed images of external world onto layer of neurons (retina) in back
How is light focused?
bending of light through refraction
What parts of the eyes are responsible for refraction?
cornea and lens
What is the transparent outer layer of eye, whose curvature is fixed? Forms image on retina
cornea
What is the structure in eye that helps focus an image on the retina? Fine tunes image on retina
lens
What are the muscles that control the shape of lens inside the eye, focusing on image on the retina?
ciliary muscles
What is the process to bring nearby objects into focus?
accommodation
What is the mechanism of accommodation?
ciliary muscles adjust the lens
What is myopia?
nearsightedness; inability to focus retinal image of objets that are far away
Why does myopia develop?
develops if eyeball is too long
What photoreceptor cells are active at low levels of light?
rods
What photoreceptor cells are sensitive to color?
cones
What type of cells form the optic nerve?
ganglion cells
What type of cell receives info from rods/cones and passed info to retinal ganglion cells?
bipolar cells
What is the order of processing in retina?
photoreceptors (rods/cones) –> bipolar cells –> ganglion cells –> optic nerve
What is the scotopic system?
system in retina that operates at low levels of light and involves RODS; includes convergence
What is the photopic system?
system in retina that operates at high levels of light and involves CONES; less convergence
What is convergence?
many neural cells send a signal to one cell
How can the eye deal with a large range of light intensities?
changing the size of the pupil (dilation + constriction)
What nervous system is pupil dilation associated with?
sympathetic nervous system (fight or flight)
What nervous system is pupil constriction associated with?
parasympathetic nervous system (rest and digest)
