CPOT Contact Lens Fitting & Patient Care

Question 1

Which contact lens material has the highest oxygen transmissibility (Dk/t)?

Accepted Answer

Silicone hydrogel

Answer

Silicone hydrogel lenses allow significantly more oxygen to reach the cornea than conventional hydrogel or PMMA lenses because the silicone component is highly oxygen-permeable.

Question 2

Which contact lens design is used to correct astigmatism?

Accepted Answer

Toric lens

Answer

Toric lenses have different powers in different meridians and include stabilization features to correct astigmatism by staying properly oriented on the eye.

Question 3

What does the measurement 'Dk/t' represent in contact lens specifications?

Accepted Answer

Oxygen transmissibility

Answer

Dk/t represents oxygen transmissibility, where Dk is the material's oxygen permeability and t is the lens center thickness; higher values mean more oxygen reaches the cornea.

Question 4

Which contact lens replacement schedule carries the lowest risk of deposit buildup?

Accepted Answer

Daily disposable

Answer

Daily disposable lenses are discarded after each use, eliminating the accumulation of protein, lipid, and calcium deposits that build up on reusable lenses over time.

Question 5

What is the base curve of a contact lens?

Accepted Answer

The central posterior radius of curvature

Answer

The base curve is the radius of the central posterior (back) surface of the contact lens; it must closely match the corneal curvature to achieve an appropriate fit.

CPOT - Certified Paraoptometric Technician Practice Test

CPOT - Certified Paraoptometric Technician Practice Test

CPOT Contact Lens Fitting & Patient Care