Sun Smarts
Name two lens materials that have built-in UV protection.
Polycarbonate and Trivex
What is the primary benefit of anti-reflective coating?
Reduces glare and reflections
A 40-year-old accountant who works on a computer all day
AR coating, possibly blue light filter, anti-fatigue
What is the most common method used to tint plastic lenses?
Immersion/dip dyeing
Why don’t photochromic lenses activate well inside a car?
Most windshields block UV light.
What type of lens cuts horizontal glare from water and roads?
Polarized
What’s the name of the top layer that repels water and oil on premium AR coatings?
Hydrophobic or oleophobic coating
A fashion-focused adult who wants invisible lenses in photos
Anti-reflective coating
Which lens material is the most difficult to tint and why?
Polycarbonate – it’s resistant to absorbing dyes due to its chemical makeup
True or False: CR-39 lenses always come with scratch-resistant coating.
False – it must be added.
True or False: Polarized lenses provide UV protection on their own.
False – polarization and UV protection are separate features.
How can you tell if a lens has AR coating by looking at it?
It may reflect a green, blue, or purple hue when held at an angle.
A long-distance truck driver
Polarized sunglasses, AR coating for night driving, possibly photochromic
True or false: The best thing that may be used to clean a tint tank that has burnt-on pigment is steel wool.
False
You’re finishing a high-index lens for a rimless mount and the order calls for faceting.
What is faceting, what is its primary purpose, and what must you consider when selecting lens material for this process?
Faceting is the process of beveling the lens edge at an angle for cosmetic or structural purposes, often in rimless designs.
Its main purpose is aesthetic enhancement and reducing visible edge thickness.
You must use durable lens materials like polycarbonate or high-index—softer materials like CR-39 can chip or crackduring mounting.
What’s one downside of polarized lenses for certain professions or tasks?
They can interfere with reading LCD screens (e.g., pilots, photographers).
What’s a downside to basic AR coatings without hydrophobic layers?
Smudge easily or hard to clean
A senior citizen with light sensitivity indoors and outdoors wants a single pair of lenses. Suggest a treatment combo.
Photochromic, AR, and UV protection.
A patient requests gradient brown lenses. What does “gradient” mean and how is it achieved?
Gradient = darker at the top, lighter at the bottom; achieved by adjusting time in the tint bath or lowering the lens gradually during the process.
A patient’s high-index lenses with photochromic and AR coatings show spiderweb-like surface fractures after a few months. What’s the term for this defect and what could have caused it?
The defect is called crazing and could have been caused by heat, stress on the lenses from the frame, and/or using alcohol or ammonia-based cleaners.
Why are mirrored lenses sometimes paired with tinted or polarized lenses?
They reflect more light, reducing eye strain in intense sunlight.
Which type of lens—glass or plastic—benefits more from AR coating in terms of glare control?
Glass lenses, due to higher index and more surface reflection.
A motorcyclist wants lenses that reduce glare from the road without compromising visibility of their dashboard. What treatment is best?
Polarized lenses may not be ideal—photochromic or solid tint with AR might be better.
What are 2 reasons your tinted lens may appear splotchy?
The lens was not properly cleaned and/or the lens cured unevenly during manufacturing.
You’re inspecting a pair of polarized lenses mounted in semi-rimless frames. After a few weeks, the lenses show separation at the edges, and a hazy film has formed in the lens. What is this defect and what could have caused it?
This defect is called delamination caused by the layers splitting from either grooving in the wrong place or a too-tight cord.