Contact Lens Fitting and Care Flashcards

Which solution type is contraindicated for use with hydrogen peroxide contact lens disinfection systems during the neutralization step?

Answer: Multi-purpose solution

Multi-purpose solutions must not be used to neutralize hydrogen peroxide systems; the dedicated neutralizing disk or tablet must be used to avoid ocular damage.

A soft toric contact lens rotates 15 degrees counterclockwise on the eye. If the prescription calls for 180-degree cylinder axis, what axis should be ordered?

Answer: 165 degrees

Using the LARS rule (Left Add, Right Subtract), a counterclockwise rotation means you subtract 15 degrees: 180 − 15 = 165 degrees.

Which condition is an absolute contraindication to contact lens wear?

Answer: Active bacterial keratitis

Active corneal infection such as bacterial keratitis is an absolute contraindication because contact lens wear would worsen the infection and delay healing.

What is the recommended maximum replacement interval for rigid gas permeable (RGP) contact lenses?

Answer: 1–2 years

RGP lenses are typically replaced every 1–2 years, though this depends on lens deposits, surface degradation, and prescription changes.

A patient reports their daily wear soft contact lenses feel dry and uncomfortable by midday. Which product is most appropriate to recommend for in-eye use?

Answer: Rewetting drops formulated for contact lenses

Rewetting drops designed for contact lens wear are safe for in-eye use and help rehydrate the lens surface without disrupting the tear film.

When assessing the fit of a soft contact lens using a slit lamp, a well-fitting lens should demonstrate how much movement on a blink?

Answer: 0.25–0.50 mm

A properly fitting soft contact lens should move approximately 0.25–0.50 mm with each blink to ensure adequate tear exchange and corneal oxygenation.