Visual Function

Question 1

is a complex function involving image formation, reception by photoreceptors, transmission of sensory information to appropriate brain centers, and perception of the image in the mind.

Answer 1

Human vision

Question 2

Functions of human eye

Answer 2

image formation
reception
transmission
perception

Question 3

is the sharpness of the visual image and is often tested in clinics with the Snellen eye test.

Answer 3

Acuity

Question 4

is abnormal curvature of the cornea or lens.

Answer 4

Astigmatism

Question 5

is the ability to adjust the focusing apparatus to account for changes in distance from the viewed object.

Answer 5

Accommodation

Question 6

Your ___ changes shape to accommodate near vision. Likewise, your ___ changes diameter to help accommodation.

Answer 6

lens, pupil

Question 7

The ___ is actually the optic disk, a point where there are no photoreceptors in the retina. The part of the visual field focused on this cannot be seen. We normally do not notice it because the brain “fills in” the blank area for us.

Answer 7

blind spot

Question 8

are photoreceptors adapted to reception of dim light of a broad color range (i.e., dim-light black-and-white vision).

Answer 8

Rods

Question 9

are adapted for bright-light color vision because they require higher light intensity, but different __ can perceive different wavelengths (colors) of light.

Answer 9

Cones

Question 10

The cones are densest at the __, and the rods are densest in the ___ portion of the visual field.

Answer 10

fovea, peripheral

Question 11

____, or color vision deficiency, can be the result of brain or nerve damage, but it is usually an inherited condition. In the more common forms, called red-green deficiency, red- or green-sensitive cones are missing or defective.

Answer 11

Color blindness

Question 12

Individuals with no green-sensitive cones have ___;

Answer 12

deuteranopia

Question 13

those with no red-sensitive cones have ___.

Answer 13

protanopia