Eye Terminology, Anatomy, and Diseases

Question 1

Define Myopia and give a prescription example.

Answer 1

Myopia is when the focal point of a distant object is in front of the retina (nearsightedness). Example, -1.25

Question 2

Define Hyperopia and give a prescription example.

Answer 2

Hyperopia is when the focal point of a distant object is in back of the retina (farsightedness). Example, +1.25

Question 3

What is emmetropia?

Answer 3

Emmetropia is defined as a normal eye.

Question 4

What is ammetropia?

Answer 4

When the eyes do not focus on the retina, its forms include myopia (nearsightedness), hyperopia (farsightedness), and astigmatism.

Question 5

What are the lacrimal glands and what’s its function?

Answer 5

The lacrimal glands are part of the lacrimal system and secrete tears constantly to keep the surface of the eye moist. This is to keep the eye clear of any foreign material and keep the cornea in a liquid environment to maintain transparency.

Question 6

What does the palpebra do?

Answer 6

The palpebra, the eyelids, form a protective, moveable shield in front of the eyes and orbits. They contain several glands that secrete lipid and sebaceous fluids to lubricate the eye and form a precorneal film.

Question 7

Define strabismus.

Answer 7

Strabismus refers to the nonalignment of the eyes, such that an object in space is not visualized simultaneously by the macula of each eye. Single, binocular vision will not be present. Consequently, double vision and/or suppression of one eye will likely occur.

Question 8

Define phoria.

Answer 8

A phoria refers to the potential or tendency for an eye to turn or deviate when binocular vision is broken.

Question 9

Define tropia

Answer 9

Tropia is when the eye is deviated when the patient is looking with both eyes.

Question 10

Define refraction

Answer 10

The process of light rays from an illuminated object transmitting through the transparent media of the eye to the photoreceptor cells of the retina.

Question 11

Name the five layers of the cornea

Answer 11

The five layers are: epithelium, Bowman’s membrane, the stroma, Descemet’s membrane, and the choroid.

Question 12

What is the iris?

Answer 12

The iris is a circular curtain suspended between the anterior and posterior chambers and is actually a continuation of the blood vessels in the choroid. It has two sheets of muscles that dilate and constrict the pupil to regulate the amount of light entering the eye. A layer of pigment cells gives the iris its color and assist in darkening the interior of the eyeball.

Question 13

What is the crystalline lens?

Answer 13

The crystalline lens is biconvex, transparent body consisting of an outer capsule and inner substance called cortex and nucleus. In the young, the lens is flexible and capable of changing shape to provide variable focus power (accommodation). In the latter years, the lens hardens and presbyopia results.

Question 14

What are rods and cones?

Answer 14

Rods and cones are the photoreceptors of the retina.

Question 15

What’s the rods role?

Answer 15

Rods are primarily located in the peripheral area and are associated with detecting movement and vision in dim light.

Question 16

What’s the cones role?

Answer 16

Cones provide color recognition as well as sharp images in brighter light conditions.

Question 17

How many muscles does the human eye have? Name them.

Answer 17

The human eye has six muscles. These muscles are named the superior rectus, inferior rectus, lateral rectus, medial rectus, superior oblique, and inferior oblique.

Question 18

What is the blind spot of the eye and why?

Answer 18

The optic disc is the blind spot of the eye. It is so, because neither rods nor cones are present.

Question 19

What is glaucoma?

Answer 19

The optic disc is the blind spot of the eye. It is so, because neither rods nor cones are present.

Question 20

Define amblyopia.

Answer 20

Amblyopia, also called “lazy eye,” is decreased vision in the deviating eye due either to strabismus or an uncorrected refractive error.

Question 21

What is cataract?

Answer 21

Cataract is when there are opacities in the crystalline lens or better known as a clouding of the lens.

Question 22

Simple hyperopic astigmatism

Answer 22

Example; pl +1.00 x 180 transposed (+1.00 -1.00 x 90)

Question 23

compound hyperopic astigmatism

Answer 23

Example; +1.00 +0.50 x 70 transposed (+1.50 -0.50 180)

Question 24

Simple myopic astigmatism

Answer 24

Example; pl -1.00 x 180 transposed (+1.00 -1.00 x 90)

Question 25

Compound myopic astigmatism

Answer 25

Example; -1.25 -0.50 x 180 transposed (-1.75 +0.50 x 180)

Question 26

Mixed astigmatism

Answer 26

Example; -0.75 +1.25 x 180. There is -0.75 D in the 180-degree meridian and there is hyperopia of +0.50 D in the 90-degree meridian.

Question 27

Define Aphakia and give the most common cause.

Answer 27

Absence or loss of the eye’s natural crystalline lens. Mostly due to cataract surgery.

Question 28

Keratoplasty

Answer 28

Is cornea transplant surgical procedure to replace part of your cornea with corneal tissue from a donor.