The Eye Flashcards
What is the sclera
Tough outer coat. Visible white part of the eye.
What is the choroid layer
Middle layer of eyeball. Deeply pigmented to absorb light and prevent internal reflection. Contains lots of blood vessels.
What is the retina
Innermost layer in eye. Contains many rods and cones + fibre nerves.
What is the optic nerve
Carries nerve impulses from the retina directly.
What is the fovea (yellow spot)
Part of the retina where cones are concentrated these enables us to see colours in bright light
What is the conjunctiva
Transparent layer the protects cornea
What is the cornea
Transparent window at front of eye. Allows light to pass through
What is the iris
Coloured ring of tissue behind cornea. Controls amount of light entering the eye by changing size of pupil.
What is the pupil
Hole in centre of iris - size is controlled by radial and circular muscles of iris
What is the ciliary body/ciliary muscle
Contains muscles which can contact or relax to change thickness of lens
What is the suspensory ligament
Hold lens in position
What is the lens
Clear part behind the iris that helps to focus light onto the retina. Helps to focus on far and close objects
The retina consists of _________ and _________
Rods and cones
________ see in dim light
Rods see in dim light
________ see in bright light
Cones
________ see black and white vision while _________ see colour
Rods Cones
_________ are found throughout the retina
Rods
___________ are concentrated in the yellow spot
Cones
What are the 2 types of muscle around the iris
Circular and Radial
When the circular muscle contracts, the pupil gets _____________
Smaller
When the radial muscle contracts, the pupil gets ____________
Bigger