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