Biology - The Eye

The purpose of the iris in the mammalian eye is to

• focus the light coming into the eye

• detect the image coming into the eye

• control the amount of light coming into the eye

• determine the color of the image coming into the eye

The number of extrinsic muscle that control the movement of the human eye is

• 2

• 4

• 6

• thousands

The black circle in the front of the eye allows light to enter the eye

• iris

• pupil

• cornea

• fovea centralis

What is the Conjunctiva?

• a clear thin membrane that covers the optic nerve

• a clear and thin membrane that covers the entire sclera

• a clear and sensitive part found only on the external eye lids that react to bacteria

• a clear, thin membrane that covers part of the front surface of the eye and the inner surface of the eyelids

Which of the following eye materials/structures are not involve with the refraction of light (focusing) ?

• lens

• retina

• cornea

• vitreous humour

• aqueous humour

Suspensory ligament of lens connect to the

• Pupil

• Cornea

• Sclera

• Ciliary muscles

The Blind spot is caused by

• a hole in the pupil

• too much light that damages the retina

• a lack of receptors where the optic nerve and blood vessels leave the eye

• too many receptors where the optic nerve and blood vessels leave the eye

A structure that carries messages from the eye to the brain

• retina

• macula

• optic nerve

• olfactory nerve

• blood vessels in the choroid coat

Accommodation of the eye the refers to

• the ability of the ciliary muscles to change the shape of the lens

• the ability of the iris to control the amount of light that enters the eye

• the ability of the ciliary muscles to change the shape of the eye ball

• the ability of the brain to interpret the meaning of an image that is upside down

A gel-like substance that preserves the eye shape and refracts light is

• ciliary body

• clotted blood

• vitreous humour

• aqueous humour