NOCE Ophthalmic Products and Materials 4

Question 1

Which coating type reduces internal lens reflections visible to others looking at the wearer's eyes?

Accepted Answer

Anti-reflective coating

Answer

Anti-reflective coatings reduce reflections on both lens surfaces, making lenses more cosmetically transparent so others can see the wearer's eyes clearly.

Question 2

A patient's polycarbonate lenses show crazing (fine surface cracks). The MOST likely cause is:

Accepted Answer

Contact with solvents or chemical cleaners

Answer

Polycarbonate is sensitive to many solvents and harsh chemical cleaners, which cause stress crazing — a network of fine surface cracks.

Question 3

What is the main function of a hydrophobic coating on an ophthalmic lens?

Accepted Answer

Repels water and reduces smudging

Answer

Hydrophobic (water-repelling) coatings cause water to bead and roll off the lens surface, reducing smearing from rain, sweat, and fingerprints.

Question 4

The base curve of an ophthalmic lens is BEST described as:

Accepted Answer

The curvature of the front surface measured in diopters

Answer

The base curve refers to the front surface curve of the lens, expressed in diopters, which helps maintain proper optical performance and cosmetic appearance.

Question 5

Which sunglass lens tint color is generally BEST for enhancing contrast in low-light or overcast conditions?

Accepted Answer

Yellow/amber

Answer

Yellow and amber tints filter short-wavelength blue light and enhance contrast, making them ideal for low-light conditions like overcast days or dawn/dusk driving.

NOCE - National Opticianry Competency Examination Practice Test

NOCE - National Opticianry Competency Examination Practice Test

NOCE Ophthalmic Products and Materials 4