ABO NOCE Basic Opticianry Ophthalmic Products and Materials Questions and Answers 2

Question 1

Photochromic lenses darken when exposed to UV light because they contain:

Accepted Answer

Silver halide crystals (glass) or organic photochromic molecules (plastic) that undergo a reversible chemical reaction when exposed to UV

Answer

A permanent tint that darkens with heat

Answer

A liquid crystal layer that polarizes in sunlight

Answer

Reflective coatings that block UV

Question 2

Polarized lenses reduce glare primarily by:

Accepted Answer

Absorbing horizontally polarized light reflected from flat surfaces such as water, roads, and snow

Answer

Reflecting all light above a certain intensity back at the source

Answer

Using a variable density filter activated by bright light

Answer

Blocking UV light that causes surface glare

Question 3

Which characteristic of a sunglass lens is described by the term 'luminous transmittance'?

Accepted Answer

The percentage of visible light that passes through the lens

Answer

The percentage of UV light blocked by the lens

Answer

The warmth of the lens tint color

Answer

The ability of the lens to reduce glare

Question 4

A patient asks about the difference between standard single vision and aspheric lens designs. The key advantage of aspheric lenses is:

Accepted Answer

Reduced lens thickness, weight, and peripheral aberrations compared to spherical designs

Answer

Higher impact resistance than spherical lenses

Answer

Greater UV protection built into the material

Answer

Automatic darkening in sunlight

Question 5

Blue light blocking lenses have become popular. Which part of the visible spectrum do they primarily filter?

Accepted Answer

The high-energy visible (HEV) blue-violet light range, approximately 380–450 nm

Answer

The red wavelengths (620–700 nm)

Answer

The green spectrum (500–565 nm)

Answer

UV-A radiation (315–400 nm)

Question 6

Which lens coating is typically applied FIRST to a plastic lens blank before other coatings are added?

Accepted Answer

Hard coat (scratch-resistant coating)

Answer

Anti-reflective (AR) coating

Answer

UV-absorbing coating

Answer

Hydrophobic top coat