Core Terminology 6: Eye

Question 1

Sense organ

Answer 1

an organ formed as a result of the concentration of receptors with the same function.

Question 2

Photoreceptor

Answer 2

receptors in eye; that detect light stimuli.

Question 3

Conjunctiva

Answer 3

mucous membrane covering the front of eye and eyelid.

Question 4

Sclera

Answer 4

white, outer layer of eye that makes up the eyeball; maintains shape of eyeball.

Question 5

Cornea

Answer 5

front transparent part of sclera; helps with refraction.

Question 6

Iris

Answer 6

pigmented colour part of eye; controls amount of light that enters the eye.

Question 7

Pupil

Answer 7

opening that allows light to enter.

Question 8

Refraction

Answer 8

bending of light.

Question 9

Choroid

Answer 9

dark pigmented vascular layer of eye (middle); provides eye with O2 & nutrients; also prevents reflection of light.

Question 10

Ciliary body

Answer 10

front part of choroid

Question 11

Suspensory ligaments

Answer 11

structures that holds lens in position.

Question 12

Lens

Answer 12

elastic, transparent, biconvex structure that allows light through; changes shape to refract light onto retina.

Question 13

Retina

Answer 13

inner layer of eye that contains the photoreceptors (rods + cones).

Question 14

Rods

Answer 14

photoreceptor that reacts when light is low (poor); give rise to black and white vision.

Question 15

Cones

Answer 15

photoreceptors that reacts to high light intensities; give rise to colour vision

Question 16

Yellow spot

Answer 16

area in retina; contains the most photoreceptors.

Question 17

Fovea centralis

Answer 17

area in middle of yellow spot where only cones occur; sharpest vision.

Question 18

Blind spot

Answer 18

place where optic nerve leaves the eyeball; no rods or cones; no vision.

Question 19

optic nerve

Answer 19

The nerve that carries impulses from the retina to the brain

Question 20

Aqueous humour

Answer 20

watery fluid between lens and cornea

Question 21

Vitreous humour

Answer 21

jelly-like substance filling the posterior cavity behind lens; maintains shape of eyeball.

Question 22

Pupil mechanism

Answer 22

automatic (reflex) response to regulate amount of light that enters the eye.

Question 23

Eye accommodation

Answer 23

process where the eye adapts/ adjust for the observation of near or far objects; by changing the shape of the lens.

Question 24

Binocular vision

Answer 24

type of vision that provide a wider field of vision; creates a perception of depth (3D).

Question 25

Myopia

Answer 25

short-sightedness; visual defect when a person can see close objects clearly but distant objects are out of focus; corrected with concave lenses.

Question 26

Hypermetropia

Answer 26

far-sightedness; visual defect where a person can see far objects clearly, but not close objects; needs convex lenses to correct

Question 27

Cataracts

Answer 27

clouding of lens; affecting vision; corrected with surgery.

Question 28

Astigmatism

Answer 28

A disorder of the eye caused by the curvature of the lens or cornea being uneven, resulting in distorted images

Question 29

Colour blindness

Answer 29

condition when certain colours cannot be distinguished