§5.3 Flashcards
What is the function of the iris?
To control the amount of light that enters the eye, because the sensory receptors in your eyes are sensitive to light
What is the pupil?
The coloured part surrounding your eye
Why is in bright light your pupil smaller than in dark light?
In bright light the iris constricts and makes the pupil smaller, this decreases the amount of light that enters the eye. In dim light the iris makes the pupil larger to allow more light
What is the cornea?
A transparent layer. It bends incoming light rays and directs them to the eye and protects and covers the iris and pupil.
What is the lens
The lens helps to focus light rays into a clear sharp image and turns the upside down imagine the right way up
What does the retina?
It contains rods and cones, cones function well in bright light and make you see colours. Rods produce grey or black and white images
What is the fovea?
The most sensitive part of the retina. It contains many cones when you focus at an object it’s image will be directed onto the fovea
What is the optic nerve?
Where the nerve impulses are transmitted to
What is your blind spot?
The only part of the retina that does not contain light sensitive cells.
What is the sclera?
The white, outer covering of the eye, which gives the eye it’s shape and strength to prevent damage
What is the vitreous body?
The jellylike fluid in the eye which gives it it’s shape
What do your muscles do when you look to something far away?
They relax
What do your muscles do when you look to something close by?
They contract
What do your ligaments do when you look to something far away?
They are tightened
What do your ligaments do when you look to something that is close by?
They slack
