NOCE Contact Lens Fitting and Care

Question 1

Which measurement is most critical when fitting a spherical soft contact lens for proper centration and comfort?

Accepted Answer

Horizontal visible iris diameter (HVID)

Answer

HVID is used to select the correct contact lens diameter to ensure proper centration and limbal clearance.

Question 2

A patient presents with a base curve of 7.80 mm on their current contact lens and complains of lens tightness. What adjustment should be made?

Accepted Answer

Increase the base curve to 8.00 mm

Answer

A flatter (larger) base curve provides more movement and reduces the tight fit sensation.

Question 3

What does a fluorescein pattern showing central pooling (dark ring around center) indicate in a rigid gas permeable (RGP) lens fit?

Accepted Answer

Steep fit

Answer

Central pooling of fluorescein beneath an RGP lens indicates the lens is fitting steeper than the cornea.

Question 4

Which contact lens wearing schedule requires the most stringent patient education regarding infection risk?

Accepted Answer

Extended wear (overnight)

Answer

Extended wear lenses significantly increase the risk of microbial keratitis due to reduced oxygen transmission and disrupted tear film during sleep.

Question 5

A patient with presbyopia wants contact lenses. Which design uses different optical zones on a single lens to provide both distance and near vision?

Accepted Answer

Simultaneous vision multifocal

Answer

Simultaneous vision multifocal contact lenses have concentric or aspheric zones that present both distance and near prescriptions to the eye at the same time.

NOCE - National Opticianry Competency Examination Practice Test

NOCE - National Opticianry Competency Examination Practice Test

NOCE Contact Lens Fitting and Care