M14: The Eye

Question 1

When the lens of the eye is no longer transparent (i.e. cloudy areas in the lens) is referred to as what?

Answer 1

cataracts

Question 2

What is emmetropia?

Answer 2

Normal Vision (20/20)

Question 3

The vision condition in which close objects are seen clearly, but objects farther away appear blurred, goes by what two names?

Answer 3

myopia or nearsightedness

Question 4

The vision condition in which people can see distant objects very well, but have difficulty focusing on objects that are up close, goes by what two names?

Answer 4

Hyperopia or farsightedness

Question 5

What are the name(s) of the condition described below:

• conjunctiva get damaged or irriated
• can have either a bacterial infeciton or other type of irrtation like allergies
• obvious signs include redness, discharge and itching

Answer 5

Conjunctivitis or pinkeye

Question 6

The eyelashes are associated with unusually large sebaceous glands. What is it called when there is an infection of one of these glands? It usually forms along your eyelid

Answer 6

sty

Question 7

What is the name of the eye condition when the white part of the eye is swollen, red, tender or painful (inflammed)?

Answer 7

scleritis

Question 8

What is the name of the eye condition when there is a pooling/collection of blood inside the front/anterior chamber of the eye (between the iris and the ocrnea) and is usually caused by an injury?

Answer 8

hyphema

Question 9

What is the name of the vision condition that causes blurred vision (distant and near) due irregular shape of the cornea or curvature of the lens?

Answer 9

astigmatism

Question 10

The “accessory structures” of the eye provide what to the eye (i.e. what are the three main functions)?

Answer 10

Protection

Lubrication

Support

Question 11

How many distinct tunics/layers does the eye contain?

Answer 11

three

Question 12

The Fibrous Tunic (aka the 1st Layer or Outer Layer) consists of what two main structures?

Answer 12

sclera and cornea

Question 13

The Neural Tunic is the innermost layer of the eye and is also known as what structure?

Answer 13

the retina

Question 14

The retina (neural tunic) contains photoreceptors called ____ and ____.

Answer 14

rods and cones

Question 15

Which do we have more of, rods or cones?

Answer 15

we have more rods than cones

Note: we have approximately some 120 million rods, while we only have 6 to 7 million cones.

Question 16

Which type of photoreceptor is sensitive to color and more concentrated in the central yellow spot known as the macula?

Answer 16

cones

Question 17

Whic type of photoreceptor is more sensitive but not sensitive to color?

Answer 17

rods

Question 18

What the three types of cones (i.e. colors)?

Answer 18

red

blue

green

Question 19

Which tunic/layer contains numerous blood vessels, lymphatic vessels and intrinsic muscles?

Answer 19

Vascular Tunic (aka 2nd Layer or Intermediate Layer)

Question 20

What structure is part of the Vascular Tunic that helps regulate the amount of light that enters the eye?

Answer 20

the iris

Question 21

What is the name of the thin, watery fluid that fills the space between the cornea and the iris and is responsible for delivering nutrients?

Answer 21

aqueous humor

Question 22

Which tunic has the following functions:

• Providing a route for blood vessels and lymphatics.
• Regulating the amount of light (aka Iris) that enters the eye.
• Secreting and reabsorbing the aqueous humor
• Controlling the shape of the lens.

Answer 22

The Vascular Tunic (Intermediate Layer)

Question 23

Do any rods lie within the macula?

Answer 23

No

Question 24

Together with the lens, the cornea refracts light, accounting for approximately _______ of the eye’s total optical power.

Answer 24

Together with the lens, the cornea refracts light, accounting for approximately two-thirds of the eye’s total optical power.