Eye Anatomy

Question 1

Anterior chamber

Answer 1

Behind the cornea, in front of iris the area is filled with clear fluid called aqueous humor

Question 2

Aqueous humor

Answer 2

A clear watery fluid produced by the ciliary body that fills the posterior and anterior chambers. It provides nutrients and carries away waste product. It’s responsible for keeping the IOP because it is the only fluid that is continuously produced by the eye.

Question 3

Choroid

Answer 3

Made mostly of blood vessels that nourish the retina. It’s sandwiched between the retina and the sclera.

Question 4

Ciliary muscle

Answer 4

Muscle inside the eye that alters the shape of the lens. It has direct control over the focusing ability of the eye (accommodation)

Question 5

Conjunctiva

Answer 5

Clear layer covering the sclera and the inner layer of the eyelid. The pampered conjunctiva lines the lid and the bulbar conjunctiva lines the sclera

Question 6

Cornea

Answer 6

Clear transparent tissue located on the anterior of the eye. It is the most powerful refractive media and provides most of the eyes ability to focus light. It’s curvature is slightly move than the rest of the globe. It has 5 layers (epithelium, bowman’s, stroma, descemet’s membrane, endothelium). The junction of the sclera and cornea is called the limbus. The cornea is avascular.

Question 7

Crystalline lens

Answer 7

Provides focusing power. Allows adjustment of the eye to focus from near to distance. Second most powerful refractive medium. Focuses light by changing curvature of its from surface.

Question 8

Fovea centralis

Answer 8

Area in the macula ~1.5mm in diameter. Visual acuity is the sharpest because it contains the highest number of cones (responsible for daytime and color vision)

Question 9

Fundus

Answer 9

Bottom or base of an organ, or part of a hollow organ furthest from its mouth. In optometry fungus refers to interior surface of the eye.

Question 10

Iris

Answer 10

The colored part consisting of 2 circular muscles with a hole in the middle called the pupil. The iris sphincter and dilator muscles control the size of the pupil.

Question 11

Macula

Answer 11

Central part of the retina used to see detail. 3-5mm in diameter with focal depression in the center

Question 12

Ocular adnexa

Answer 12

Adjacent structures of the eye (eyelids, lashes, eyebrows, lacrimal apparatus, tarsal plates, orbit, extraocular muscles and conjunctiva.

Question 13

Optic disk

Answer 13

Appearance of the optic nerve when viewed through the pupil. It’s a physiological blind spot. The appearance of the disc can determine healthiness of the nerve

Question 14

Optic nerve

Answer 14

Carried impulses from retina to brain, transmits info from rods and cones

Question 15

Orbit

Answer 15

Bony socket that contains eye and accessory organs

Question 16

Posterior chamber

Answer 16

Located inside the eye behind the iris and in front of the lens

Question 17

Pupil

Answer 17

Round hole in center of iris through which light passes. Looks black because little light comes from inside the eye

Question 18

Retina

Answer 18

The seeing part of the eye which lines the sclera and is the place where light comes into focus

Question 19

Rods

Answer 19

Photoreceptors that provide black/white vision, are most numerous (120mil) and are most sensitive (night and peripheral vision)

Question 20

Cones

Answer 20

Photoreceptors that are responsible for color vision, clear central vision, and are less numerous (6-7mil)

Question 21

Sclera

Answer 21

White portion of the eye made of tough fibrous tissue that gives shape and structure to eyeball

Question 22

Sinuses

Answer 22

Air spaces within bones.

Question 23

Suspensions ligaments

Answer 23

Long thin fibers which connect the crystalline lens to the ring of ciliary muscles

Question 24

Vitreous humor

Answer 24

Thick, clear, jelly-like substance that fills the space between the lens and retina. It supports the retina and helps keep the eye round

Question 25

Lacrimal duct

Answer 25

The drainage system for tears. As tears are produced by the lacrimal gland they drain through lacrimal duct to reach the surface of the eye.

Question 26

Lacrimal gland

Answer 26

Glad that supplies most of the tears to the eye. Located above and temporal to the eye and behind the orbital rim.

Question 27

Nasolacrimal duct

Answer 27

Drainage system for tears to leave the eye. Connected to the nasal passage. This is why the nose runs when one cries

Question 28

Medial rectus

Answer 28

Most powerful of the extraocular muscles, only action is to turn the eye toward the nose (adduction)
located on the nasal side of eye
In

Question 29

Inferior rectus

Answer 29

Primary function is to turn eye downward (depression) and also addicts the eye. It can rotate top of the eye toward the temple and bottom of eye toward the nose (extortion)
bottom of eye going back
Down and out

Question 30

Lateral rectus

Answer 30

Only action is to move eye away from nose (abduction)
Out

Question 31

Superior rectus

Answer 31

Primary action is to move eye upward (elevation) but it also adducts eye. It can rotate top of the eye toward the nose and bottom of the eye toward temple (intortion)
Up and out

Question 32

Superior oblique

Answer 32

Primary action is intortion but also responsible for depression and abduction
up and around eye
Down and in

Question 33

Inferior oblique

Answer 33

Only extraocular muscle that has its origin in front of the orbit. Its primary action is extorsion. Also responsible for elevation and abduction
below and around*
Up and in