2: Structures of the eye Flashcards
(13 cards)
Define the cornea
The cornea is the clear, curved front part of the eye that starts to bend light inward to help focus it
Define the aqueos humour
The aqueos humour is a watery fluid that keeps the eyeballs shape, feeds the eye with nutrients and oxygen and removes waste
Define the iris
The iris is a circular coloured muscle
Define the lens
The lens is a transparent, flexible, convex structure that changes shape to focus the light onto the retina
Define the pupil
The pupil is an adjustable opening in the iris that changes size to control how much light enters the eye
(shrinking in bright light and widening in the dark or during arousal)
Define the ciliary muscles
The ciliary muscles are attached to each end of the lens and enables the process of accomodation
(Accommodation is the process where the lens changes shape to focus. It bulges for close objects (when ciliary muscles contract) and flattens for distant objects (when the muscles relax))
Define the retina
The retina is the light sensitive layer at the back of the eye, made up of special nerve cells called photorecpetors
Define photoreceptors
Receptor cells (either rods or cones) found at the back of the retina, that are specialised to detect and respond to light
Define fovea
A small cup-shaped area near the centre of the retina which has only cones within it and it provides high visual acuity
Define the blind spot
The part of the retina where the optic nerve leaves the eye, it has no photoreceptors, so it can’t detect light
Define the vitreous humour
Nourishes and supports the retina and helps the shape of the eyeball
Define the optic nerve
The nerve that connectst the eye to the brain
Define the occipital lobe
The area of the brain that recieves and processes visual stimuli
