Crystalline Lens, Presbyopia and Cataracts Flashcards Preview

Dispensing Optician > Crystalline Lens, Presbyopia and Cataracts > Flashcards

Flashcards in Crystalline Lens, Presbyopia and Cataracts Deck (20)
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1
Q

The anterior-most layers of the crystalline lens are called:

a. Nucleus
b. Cortex
c. Subcapsular epithlium
d. None of the above

A

None of the above

2
Q

Cataracts will only form in the nucleus of lens.

a. True
b. False

A

False

3
Q

The amplitude of accommodation for the average 50 year old is approximately:

a. 1.00 diopter
b. 2.50 diopters
c. 4.00 diopters
d. 6.00 diopters

A

1.00 diopter

4
Q

The lens and capsule is surrounded by a fluid called vitreous humor that nourishes the capsule and lens:

a. True
b. False

A

False

5
Q

As a patient ages, the lens becomes larger and more flexible.

a. True
b. False

A

False

6
Q

Ophthalmologists always wait for a cataract to ripen before extraction.

a. True
b. False

A

False

7
Q

The type of cataract extraction that causes the least insult or injury to the eyes is called:

a. Phakoemulsification
b. Otracapsular
c. Extracapsular
d. Couching

A

Phakoemulsification

8
Q

Prolonged periods of near vision use may lead to near point stress, and the development of:

a. Myopia
b. Hyperopia
c. Astigmatism
d. Cataracts

A

Myopia

9
Q

Sitting upright and reading or working at a longer distance may help prevent near point stress.

a. True
b. False

A

True

10
Q

When the cilliary muscle contracts it moves closer to the lens equator, relaxing the zonules (suspensory ligaments) and increasing the plus power of the lens.

a. True
b. False

A

False

11
Q

A hyperopic patient with presbyopia can remove his/her glasses to see clearly at near.

a. True
b. False

A

False

12
Q

Swelling of the area of the retina that is responsible for the central vision following cataract surgery is called:

a. Corneal edema
b. Papilledema
c. Cystoid macular edema
d. None of the above

A

Cystoid macular edema

13
Q

A secondary cataract forms:

a. In the cortex
b. In the nucleus
c. In the subcapsular epithelium
d. In the posterior capsule

A

In the posterior capsule

14
Q

Cataract surgery can now be performed using a laser to remove the lens.

a. True
b. False

A

False

15
Q

Presbyopia is caused by loss of:

a. Elasticity of the capsule
b. Cilliary muscle tone
c. Elasticity of the lens
d. All of the above

A

All of the above

16
Q

A congenital cataract is the result of:

a. Traumatic injury
b. Smoking
c. Birth
d. Exposure to ultraviolet light

A

Birth

17
Q

At birth, a child will have approximately _____ diopters of accommodation:

a. 4-6
b. 8-10
c. 12-14
d. 16-18

A

16-18

18
Q

Monovision is a fitting/surgical technique used to allow one eye to see near, while the other sees in the distance. It is preferable to fit the dominant eye with the near Rx.

a. True
b. False

A

False

19
Q

The lens is composed primarily of water and protein.

a. True
b. False

A

True

20
Q

The fibers that comprise the lens are about 10nm long and _____ in shape.

a. Cresent
b. Square
c. Oval
d. Hexagonal

A

Crecent