The Eye

The front surface (or white part) of the eye is called the ______.

Sclera

Cornea

The clear tissue that covers the front of the eye

Iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

The ciliary muscle helps to _____.

change the curve of the lens when focusing

Cataracts

cloudy spots in the eye's lens that develop as we age

Strabismus

cross-eyes

When in a low light environment, the pupils will _____.

dilate

Glaucoma

excessive intraocular pressure due to accumulation of aqueous humor

Conjunctivitis

eye infection producing an inflammatory response

Hyperopia

farsightedness

The area which contains the most dense concentration of cones is the _____.

fovea

The colored part of the eye is the _____.

iris

Astigmatism

irregularity in the cornea or lens

Scotoma

loss of only the center of the visual field

Fluids of the eyeballs help to _____.

maintain the shape of the eye, refract light rays, fill the hollow inside of the eye

Choroid

middle, vascular layer of the eye, between the retina and the sclera

Myopia

nearsightedness

Nyctalopia

night blindness

Rods are receptors used for _____.

night vision

Presbyopia

oldsightedness

The three different colors that can be seen by cones are _____.

red, green, and blue

Rods and cones are contained in the _____.

retina

Diabetic retinopathy

small hemorrhages in retinal blood vessels that disrupt the O2 supply to photoreceptors

Pupil

the adjustable opening in the center of the eye through which light enters

Retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

Optic Nerve

the nerve that carries neural impulses from the eye to the brain

Lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

When an image lands on the retina, it is actually _____.

upside down and backwards

The area known as the blind spot is due to the fact that there are no receptors _____.

where the optic nerve exits the retina

Sclera

white of the eye