CPOT Contact Lens Fitting & Patient Care 2

Question 1

What does keratometry (K-readings) measure during a contact lens fitting evaluation?

Accepted Answer

Curvature of the anterior corneal surface

Answer

Keratometry measures the radius of curvature of the central anterior corneal surface in two primary meridians, which is essential for selecting the appropriate contact lens base curve.

Question 2

In contact lens fitting terminology, what does a 'steep' fit indicate?

Accepted Answer

The lens base curve is more curved than the corneal curvature

Answer

A steep fit occurs when the lens base curve is more curved than the cornea, resulting in restricted lens movement, central tear pooling, and potential corneal hypoxia.

Question 3

Which dye, viewed under cobalt blue light, is used to evaluate the tear film pattern beneath RGP contact lenses?

Accepted Answer

Sodium fluorescein

Answer

Sodium fluorescein illuminated with cobalt blue light reveals the fluorescein pattern under RGP lenses, highlighting areas of bearing (dark), alignment (thin green), and clearance (bright green pooling).

Question 4

What does the acronym 'LARS' stand for in toric soft contact lens fitting?

Accepted Answer

Left Add, Right Subtract

Answer

LARS guides axis adjustment when a toric lens rotates: if the lens rotates to the Left, Add that number of degrees to the axis; if it rotates Right, Subtract.

Question 5

What is the recommended contact lens movement with each blink during a soft lens fitting assessment?

Accepted Answer

0.25 to 1.0 mm

Answer

Adequate soft lens movement of 0.25–1.0 mm per blink ensures proper tear exchange under the lens, supporting corneal oxygenation and preventing lens adherence.

CPOT - Certified Paraoptometric Technician Practice Test

CPOT - Certified Paraoptometric Technician Practice Test

CPOT Contact Lens Fitting & Patient Care 2