ABO NOCE Basic Opticianry Ophthalmic Products and Materials Questions and Answers 5 — Questions and Answers
Question 1: Which frame material requires soldering for repairs and adjustments?
- Metal frames (monel, stainless) (Correct answer)
- Zyl/cellulose acetate frames
- Nylon frames
- Ultem frames
Correct answer: Metal frames (monel, stainless)
Metal frame repairs typically require soldering to reattach broken parts or reinforce stress points, unlike plastic frames which are heat-adjusted or replaced.
Question 2: What is the optical significance of a lens with a higher Abbe number?
- Less chromatic aberration and better color fidelity (Correct answer)
- Greater scratch resistance
- Stronger UV protection
- Faster photochromic response
Correct answer: Less chromatic aberration and better color fidelity
A higher Abbe value (also called V-value or constringence) means the material disperses light into its color components less, resulting in less chromatic aberration.
Question 3: A patient complains that their new lenses cause rainbows around lights at night. This is most likely caused by:
- Residual surface reflections from AR coating
- Lens material with low Abbe value causing chromatic aberration (Correct answer)
- Incorrect pupillary distance measurement
- Lens tint being too dark
Correct answer: Lens material with low Abbe value causing chromatic aberration
Chromatic aberration from low Abbe value lens materials causes light to split into rainbow-like color fringing, especially noticeable around point light sources at night.
Question 4: Which lens design feature helps a wearer using digital devices by providing an extended intermediate zone?
- Office/computer progressive lens (Correct answer)
- Standard progressive lens
- Bifocal lens
- Single vision distance lens
Correct answer: Office/computer progressive lens
Office or computer progressive lenses (also called near variable focus lenses) are designed specifically to optimize intermediate and near vision distances for digital device users.
Question 5: What is the recommended minimum center thickness for a polycarbonate lens to meet FDA drop ball impact resistance standards?
- 1.0 mm (Correct answer)
- 2.0 mm
- 3.0 mm
- 0.5 mm
Correct answer: 1.0 mm
Polycarbonate lenses must have a minimum center thickness of 1.0 mm to meet FDA impact resistance requirements, compared to 2.0 mm for glass and CR-39.
Question 6: An oleophobic coating on an ophthalmic lens is designed to:
- Repel oils and fingerprints from the lens surface (Correct answer)
- Block UV light
- Reduce fogging
- Increase hardness
Correct answer: Repel oils and fingerprints from the lens surface
Oleophobic coatings repel oils from skin and fingerprints, making the lens surface easier to wipe clean and reducing smudging.
Question 7: Which of the following best describes the difference between photochromic and polarized lenses?
- Photochromic lenses darken in UV light; polarized lenses block reflected glare regardless of tint level (Correct answer)
- Polarized lenses darken in UV light; photochromic lenses block glare
- Both darken in UV light but differ in color options
- Both block glare but photochromic lenses do so only when dark
Correct answer: Photochromic lenses darken in UV light; polarized lenses block reflected glare regardless of tint level
Photochromic lenses change tint based on UV exposure while polarized lenses filter reflected horizontal glare through a fixed polarizing filter regardless of their current tint level.
ABO NOCE Basic Opticianry Ophthalmic Products and Materials Questions and Answers 5
Which frame material requires soldering for repairs and adjustments?