FREE ABO Contact Lenses Questions and Answers

Question 1

When comparing silicone hydrogel contact lenses to conventional hydrogel lenses, what is the main mechanism that enhances oxygen permeability?

Accepted Answer

By incorporating silicone into the lens material

Answer

By thinning the lens profile

Answer

By increasing water content

Answer

By reducing the lens diameter

Question 2

Which of the following is MOST important for astigmatic patients receiving toric soft contact lens fittings in order to ensure good visual acuity?

Accepted Answer

The stabilization mechanism of the lens

Answer

The water content of the lens

Answer

The base curve of the lens

Answer

The diameter of the lens

Question 3

Why are UV-blocking compounds added to the materials used to make contact lenses?

Accepted Answer

To reduce the risk of developing cataracts and other UV-related ocular conditions

Answer

To increase the lens's resistance to protein deposits

Answer

To improve the oxygen permeability of the lens

Answer

To enhance the wettability of the lens surface

Question 4

"Apical clearance" in the context of rigid gas permeable (RGP) lens fit refers to:

Accepted Answer

The lens vaulting over the corneal apex with a thin layer of tears beneath

Answer

The lens resting directly on the corneal apex

Answer

The lens completely covering the corneal apex without touching it

Answer

The alignment of the lens edge with the limbus

Question 5

"Simultaneous vision" for presbyopia patients wearing multifocal contact lenses means:

Accepted Answer

The eye receiving images from both near and distance zones at the same time

Answer

The need to physically move the eyes to switch between near and far vision

Answer

The ability to see near and far objects clearly but not at intermediate distances

Answer

Sequential focusing on near and distant objects, requiring adjustment time

Question 6

Why are rigid gas permeable (RGP) lenses designed with a "back surface toric" design for specific corneal shapes used in this way?

Accepted Answer

To match the lens to the toric shape of the cornea for better fit

Answer

To enhance oxygen transmission through the lens

Answer

To improve lens stabilization on the cornea

Answer

To increase the lens's resistance to deposit formation

Question 7

Why is it frequently required to use a specially developed keratoconus lens instead of a conventional RGP lens when fitting contact lenses for a patient with keratoconus?

Accepted Answer

To accommodate the conical corneal shape for improved comfort and visual acuity

Answer

To provide a larger optic zone for improved peripheral vision

Answer

To increase the water content of the lens for better hydration

Answer

To reduce the oxygen permeability required for the thinned cornea

Question 8

When wearing soft contact lenses, "lens dehydration" is a problem that can cause discomfort. What is the typical cause of this problem?

Accepted Answer

Low humidity environments

Answer

High water content in the lens materials

Answer

Excessive tear production

Answer

Deceased blink rate

Question 9

The following factors are most strongly linked to the development of microbial keratitis in contact lens wearers:

Accepted Answer

Extended (overnight) wear of any contact lens type

Answer

Wearing RGP lenses with a high Dk/t value

Answer

Daily wear of silicone hydrogel lenses

Answer

Use of daily disposable lenses

Question 10

What is the main advantage of giving the surface of RGP lenses a "plasma treatment"?

Accepted Answer

To improve the wettability and surface lubricity of the lens

Answer

To increase the lens's resistance to scratches

Answer

To enhance the hydrophobic properties of the lens surface

Answer

To extend the usable life of the lens by preventing protein deposits