Unit 2B

Question 1

Cataract

Answer 1

an opacity in the lens that blocks light from reaching the retina; often occurs in an older age due to sunlight (UV) exposure

Question 2

Retinal colorblindness

Answer 2

an inability to correctly see colors due to the mutations in photoreceptors

Question 3

Monochromacy

Answer 3

a form of congenital achromatopsia (color blindness) arising from problems in the retina

Question 4

Rod monochromacy

Answer 4

rod monochromats are people whose cone photoreceptors are present in the retina but are completely non-functional. The cones cannot absorb light and therefore the patient relies only on rod vision

Question 5

Cone monochromacy

Answer 5

patient has one functioning cone type. Color vision is restricted to about 100 colors. Blue cone monochromacy is rare, but slightly more common than L/M cone monochromacy

Question 6

Dichromacy

Answer 6

color vision disorder in which one type of cone is absent or non-functioning

Question 7

Protanopia

Answer 7

L photoreceptors deficit that causes Red-Green color blindness

Question 8

Deuteranopia

Answer 8

M photoreceptors deficit that causes Red-Green colorblindness

Question 9

Tritanopia

Answer 9

S photoreceptors deficit that causes Blue-Yellow colorblindness

Question 10

Red/Green colorblindness

Answer 10

a form of retinal colorblindness where either the green cones are missing completely or respond like red cones. More common in females.

Question 11

Blue yellow colorblindness

Answer 11

a form of retinal colorblindness where people confuse blue with green and yellow with violet. It is very rare and not sex linked.

Question 12

Anomalous trichromacy

Answer 12

Patients with types of anomalous trichromacy (protanomaly, deuteranomaly, or tritanomaly) are trichromats, but the color matches they make significantly differ from normal

Question 13

Protanomaly

Answer 13

L-cone (red) spectrum shifted closer to M-cone (green) spectrum

Question 14

Deuteranomaly

Answer 14

M-cone (green) spectrum shifted closer to L-cone (red) spectrum

Question 15

Tritanomaly

Answer 15

blue-yellow discrimination altered

Question 16

Ishihara Plates

Answer 16

38 colored plates used to test those with red-green color blindness

Question 17

Tetrachromats

Answer 17

women who have 4 types of cones, which likely allows them to see about 100 million colors.

Question 18

Scotoma

Answer 18

an area impaired or lost vision in the visual field. A scotoma can arise from damage anywhere along the visual pathway from the retina to primary visual cortex. Beyond V1, more specialized types of visual disorders arise.

Question 19

Unilateral field loss

Answer 19

loss of an entire eye’s vision due to tumor or trauma that results from the disconnection of the optic nerve.

Question 20

Hemianopsia

Answer 20

blindness in one half of the visual field in one or both eyes

Question 21

Bitemporal hemianopsia

Answer 21

blindness in the outer halves of the visual field in both eyes, due to damage to the optic chiasm

Question 22

Binasal hemianopsia

Answer 22

blindness in the middle halves of the visual field in both eyes, due to damage to uncrossed fibers (often due to calcification of carotid arteries; also associated with hydrocephalus)

Question 23

Homonymous hemianopsia

Answer 23

blindness in the same hemisphere of the visual
field in both eyes, due to damage to the opposite hemisphere of cortex (often from
stroke or trauma). ‘Right homonymous hemianopsia’ refers to the loss of the right
hemifield of vision in each eye from damage to left V1