Human Vision Flashcards
What does the cornea do?
Light rays are refracted by the cornea which helps to force the light on the retina.
The cornea does most of the focusing of the light rays.
What is the iris and what does it do?
The iris is the colored part of the eye. It controls the size of the pupil and regulates the amount of light that enters the eye.
What is the pupil?
A hole in the iris that light passes through to reach the retina
What is the sclera?
The tough cover of the eyeball that forms the white part of the eye
What does the lens do?
Refines the refraction to further focus the light.
The lens gets thicker and thinner depending on the distance of the object.
What do the ciliary muscles do?
Controls the thickness of the lens.
When muscles contract, the lens becomes thicker and focuses nearby objects.
What is the retina?
The area where the image is produced and converted into nerve signals.
What does the optic nerve do?
Carries the nerve signals to the brain
How is an image produced?
The image is produced in the retina and the image is upside-down
What are the 2 types of light receptor cells?
Rods and cones
What are rods?
Help you see black and white.
There are 120 million per eye.
What are cones?
Help you see colors.
They have 3 kinds of cells each processing red, green or blue.
There are 6 million per eye.
What is the blind spot?
The area where the optic nerve enters the retina and does not have any light-sensing cells.
