L.4 - Structures & Functions of the Eye

Question 1

What is acute glaucoma?

Answer 1

A much more sudden type of glaucoma than chronic glaucoma

Acute glaucoma can lead to rapid vision loss if not treated promptly.

Question 2

Define amplitude of accommodation

Answer 2

The maximum amount that the eye’s crystalline lens can accommodate (change shape) and is recorded in diopters

This measurement indicates the eye’s ability to focus on near objects.

Question 3

What is aniridia?

Answer 3

A congenital disorder that involves a partial or complete loss of the iris

Aniridia can lead to vision problems and sensitivity to light.

Question 4

What is aniseikonia?

Answer 4

A condition in which the two eyes experience a significant difference in retinal image sizes and/or shapes

This can cause discomfort or difficulty in visual perception.

Question 5

What does anisocoria refer to?

Answer 5

When the pupil in one eye is significantly larger or smaller than the pupil in the other eye

Anisocoria can be a sign of underlying neurological issues.

Question 6

Define anisometropia

Answer 6

A condition in which a difference in refractive error exists between both eyes

This can lead to visual discomfort and requires corrective lenses.

Question 7

What is the anterior chamber of the eye?

Answer 7

The fluid-filled space inside the eye between the iris and the cornea’s innermost surface (endothelium)

It plays a crucial role in maintaining intraocular pressure.

Question 8

What is the apical zone?

Answer 8

Also known as the corneal cap, is the central portion of the cornea with a constant radius of curvature

This area is crucial for focusing light onto the retina.

Question 9

What does the aqueous layer represent?

Answer 9

The middle layer of the tear film

It provides hydration and nutrients to the cornea.

Question 10

What is Bowman’s layer?

Answer 10

Located between the epithelium and stroma, this layer is acellular and primarily composed of collagen

It provides structural support to the cornea.

Question 11

Define canthi

Answer 11

The angles at which the top and bottom lids meet (medial canthus and lateral canthus)

Canthi are important for tear drainage.

Question 12

What is the caruncle?

Answer 12

A pinkish elevation located in the center of the small triangular space at the medial canthus

It contains sebaceous and sweat glands.

Question 13

What is a cataract?

Answer 13

An opacity formed within the crystalline lens of the eye

Cataracts can lead to cloudy vision and require surgical intervention.

Question 14

Define chorioretinitis

Answer 14

A condition where the choroid and retina are inflamed

This can result from infections or autoimmune disorders.

Question 15

What is the ciliary zone?

Answer 15

The remaining portion of the iris that extends to its origin at the ciliary body

It plays a role in the eye’s focusing mechanism.

Question 16

What is the collarette?

Answer 16

The thickest region of the iris

It separates the pupillary zone from the ciliary zone.

Question 17

Define Descemet’s membrane

Answer 17

A basement membrane that emerges from the endothelium

It provides structural support to the cornea.

Question 18

What is diabetic retinopathy?

Answer 18

An eye disease where the retinal blood vessels leak due to advanced or long-term diabetes

It can lead to vision loss if not managed properly.

Question 19

What does the dilator pupillae muscle do?

Answer 19

Dilates the pupil (makes it larger)

This muscle is controlled by the sympathetic nervous system.

Question 20

What is the endothelium?

Answer 20

The innermost layer of the cornea, consisting of hexagon-shaped cells, and makes up approximately 2% of the overall corneal thickness

It is crucial for maintaining corneal clarity.

Question 21

Define epithelium in the context of the eye

Answer 21

Makes up approximately 10% of the overall corneal thickness and is the first line of defense against infection or harm

It regenerates quickly after injury.

Question 22

What is the fornix?

Answer 22

The fornices keep anything that enters the eye from moving to the back of the eye

It plays a role in tear drainage.

Question 23

What is the fovea centralis?

Answer 23

A critical area of the eye that allows people to see with exceptional clarity and precision

It contains a high density of photoreceptor cells.

Question 24

Define glaucoma

Answer 24

A disease of the eye that results in the intraocular pressure (IOP) becoming pathologically high, which can lead to blindness

Early detection and treatment are crucial to prevent vision loss.

Question 25

What is the globe?

Answer 25

The eyeball is called the globe ## Footnote It houses all the internal structures of the eye.

Question 26

What is hyphema?

Answer 26

When blood fills the anterior chamber ## Footnote It can result from trauma and may require medical intervention.

Question 27

Define iridocyclitis

Answer 27

A disorder in which the iris and ciliary body are inflamed ## Footnote This condition can cause pain, redness, and vision problems.

Question 28

What is the iris?

Answer 28

A thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil ## Footnote It regulates the amount of light that reaches the retina.

Question 29

Define lipid layer in the tear film

Answer 29

The outer, oil-based layer of the tear film that helps prevent tear evaporation and spillage ## Footnote It is crucial for maintaining ocular surface health.

Question 30

What is the macula?

Answer 30

A small and highly sensitive part of the retina with many cones, making it responsible for detailed central vision ## Footnote Damage to the macula can lead to significant vision loss.

Question 31

What is macular degeneration?

Answer 31

A chronic eye disease where the macula deteriorates, and central vision is lost ## Footnote It is a leading cause of vision impairment in older adults.

Question 32

Define miosis

Answer 32

When the pupil constricts (gets smaller) ## Footnote This response can be triggered by bright light or certain drugs.

Question 33

What is a miotic drug?

Answer 33

A type of drug that makes the pupil constrict ## Footnote These drugs are often used to treat glaucoma.

Question 34

What is the mucoid layer in the tear film?

Answer 34

The innermost layer of the tear film that sits immediately adjacent to the corneal and conjunctival epithelial cells ## Footnote It helps to spread tears evenly across the ocular surface.

Question 35

Define mydriasis

Answer 35

When the pupil dilates (gets bigger) ## Footnote This can occur in low light conditions or due to certain medications.

Question 36

What is a mydriatic drug?

Answer 36

A type of drug that makes the eyes dilate ## Footnote These are used during eye examinations to allow better visualization of the retina.

Question 37

What is ocular albinism?

Answer 37

Lack of pigment in the iris or retina ## Footnote This condition can lead to vision problems and increased sensitivity to light.

Question 38

What is the orbit?

Answer 38

The bony cavity containing the eyeball and its adjacent structures (adnexa) ## Footnote It provides protection and support for the eye.

Question 39

Define posterior chamber

Answer 39

The smallest of the three chambers located behind the iris and in front of the lens ## Footnote It houses the crystalline lens and ciliary processes.

Question 40

What are puncta?

Answer 40

Small openings located at the medial canthi that facilitate tear drainage ## Footnote Proper function of puncta is essential for tear film stability.

Question 41

What is the pupil?

Answer 41

An opening formed by the iris, located at its center; allows light to enter the retina ## Footnote The size of the pupil is adjusted to control light entry.

Question 42

What is the pupillary zone?

Answer 42

Inner region whose edge forms the boundary of the pupil ## Footnote It is distinct from the ciliary zone of the iris.

Question 43

Define radius of curvature in terms of the cornea

Answer 43

A measurement of its steepness, in millimeters ## Footnote It influences the cornea's refractive power.

Question 44

What is retinal detachment?

Answer 44

Condition where the retina separates from the choroid ## Footnote This is a medical emergency that requires immediate treatment.

Question 45

What is retinitis pigmentosa?

Answer 45

A genetic condition that can result in night blindness and a loss of peripheral vision ## Footnote It is often progressive and can lead to total vision loss.

Question 46

Define rubeosis

Answer 46

Growth of abnormal blood vessels in the iris ## Footnote This can lead to complications such as neovascular glaucoma.

Question 47

What does the sphincter pupillae do?

Answer 47

Makes the pupil smaller (constricts) ## Footnote This muscle is controlled by the parasympathetic nervous system.

Question 48

What is the stroma?

Answer 48

The middle layer of the cornea, making up 90% of its thickness; contains collagen fibers woven together at right angles called lamellae ## Footnote It provides strength and flexibility to the cornea.

Question 49

What is the tarsal plate?

Answer 49

Fibrous connective tissue that supports the eyelid ## Footnote It maintains the shape of the eyelid.

Question 50

What is the tear film?

Answer 50

Maintains hydration of the cornea and conjunctiva; promotes ocular health and clear vision ## Footnote It consists of three layers: lipid, aqueous, and mucoid.

Question 51

Define uveitis

Answer 51

Inflammation of the Uvea; the middle layer or tunic of the eye which is made up of the choroid, ciliary body, and iris ## Footnote Uveitis can cause pain, redness, and vision changes.