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

The main way that silicone hydrogel contact lenses increase oxygen permeability is by adding silicone to the lens material. Compared to conventional hydrogel materials, which rely primarily on water content to assist oxygen transmission, silicone permits noticeably more oxygen to reach the cornea.

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

For astigmatic patients, the stabilizing mechanism of toric soft contact lenses is essential to achieving the best possible isual acuity. By maintaining the lens's right orientation on the eye, this mechanism makes sure that the astigmatic correction appropriately matches the astigmatism of the eye.

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

By preventing damaging UV rays from reaching the cornea and internal structures of the eye, UV-blocking chemicals are added to contact lens materials with the aim of lowering the wearer's risk of cataract development and other ocular disorders associated with UV exposure.

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

When discussing RPG lenses, apical clearance refers to the lens's vaulting over the corneal apex while preserving a little space between the lens and the cornea that is moistened with a thin coating of tears. This fitting technique is crucial for facilitating tear exchange, improving comfort, and guaranteeing that the cornea receives enough oxygen.

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 feature of multifocal contact lenses known as "simultaneous vision" refers to the ability of the wearer's eye to simultaneously receive images from the near and far zones. Depending on the viewing distance, the brain then chooses the clearest image, enabling continuous vision at various ranges without the need for manual correction.

ABO - American Board of Optometry Practice Test

ABO - American Board of Optometry Practice Test

Free ABO Contact Lenses Questions and Answers