Visual Systems Flashcards
What is the cornea?
The cornea is a transparent, colorless protective tissue.
What is the iris?
The iris is the round, colored membrane that surrounds the pupil.
What is the pupil?
The pupil allows light to enter the eye and stimulate the retina. Opening in the center of the iris.
What is the Lens?
The lens is a transparent, bi convex membrane
What is the retina?
The retina is a thin, ten layered membrane. Which covers most of the posterior of the eye.
What are cones used for?
Photopic/day vision. Produces lodopsin. 1:1 ratio to neuron cells. Identifies colors.
What are rods used for?
Scotopic/night vision. Produces Rhodopsin. 10:1 to 10,000:1 of rod cells to neuron cells
What is mesopic vision?
Uses cones and rods. Is prevalent during dusk a dawn.
What is fovea centralis?
Within the retina, the cone cells are mostly located within the region known as the fovea centralis.
What is the optic nerve?
Where the optic nerve takes the electrical input from the retinal images and transport those signals to the brain.
What are the day retinal blind spots?
5.5 to 7.5 degrees
What are the night retinal blind spots?
5-10 degrees
What is motion parallax?
Most important cue to depth perception.
• stationary objects
• observer moving
What is the average time for initial dark adaptation?
30-45 min
After full dark adaptation, ¿how much time is required to re adapt? if exposed to bright lights.
3-5 min
