Written and maintained by CASRAI Editorial Board
Last updated
General product information, not medical advice. For eye symptoms, light sensitivity or a prescription need, see an eye care professional.
Overview
Sunglasses are sorted by lens type (polarized, photochromic, mirror-coated, gradient, amber) and by frame type (ordinary or wraparound). None of these choices tells you how much ultraviolet (UV) light a lens blocks. The American Academy of Ophthalmology (AAO) states that “the color and the degree of darkness do not tell you anything about the lenses’ ability to block UV light”, so the label is the check that matters.
In the United States, nonprescription sunglasses are a regulated medical device. Under 21 CFR 886.5850 they are spectacle frames or clips with absorbing, reflective, tinted, polarizing or photosensitized lenses, intended to protect the eyes from bright sunlight and not to provide refractive correction. They are Class I (general controls) and exempt from premarket notification (510(k)), subject to 21 CFR 886.9. That is an FDA classification, not an FDA “approval” of any particular pair.
Types table: what each type is, typical use, and where it stops
The rows below follow the AAO guide to sunglass types; the regulatory wording follows 21 CFR 886.5850.
| Type | What it is | Typical use | Limits |
|---|---|---|---|
| Polarized lenses | Lenses that cut reflected glare from surfaces | Glare off pavement, car windows and water, for example driving and fishing | “Polarization has nothing to do with UV light absorption”; check the UV label separately |
| Photochromic lenses | Lenses that darken in bright light and lighten in low light | Changing light conditions | Slow to change: most darkening takes about half a minute and lightening about five minutes |
| Mirror-coated lenses | Lenses with thin metallic layers that reduce visible light | Cutting visible brightness | Full UV protection should not be assumed; the UV label is the check |
| Single gradient lenses | Dark at the top, lighter below | Cutting sky glare; useful for driving because they do not dim the view of the dashboard | Less effective against glare reflected from snow or the beach |
| Double gradient lenses | Dark at the top and bottom, lighter in the middle | Water and snow sports | The AAO does not recommend them for driving because they make the dashboard appear dim |
| Amber lenses | Lenses that block blue light and make surroundings look yellow or orange | Activities such as skiing, hunting, boating and flying | Whether blue light harms the eye is still debated |
| Wraparound frames | Frames that curve around the face | Blocking light from entering around the edges of the frame | Ordinary frames let enough UV in around the edges to reduce the benefit of protective lenses |
Types of sunglass lenses
Lens types differ in how they handle visible light: absorbing or tinted, reflective (mirror), polarizing and photosensitized (photochromic) are the four lens treatments named in the federal definition. A single pair can combine them, for example a polarized lens with a mirror coating, but each treatment answers a different problem. Glare reduction (polarization), brightness reduction (tint, mirror) and light-adaptive darkening (photochromic) are separate from UV blocking.
Types of sunglasses frames
The federal definition covers “spectacle frames or clips”, so a clip-on counts as sunglasses just as a full frame does. For sunlight protection the distinction made by the AAO is between ordinary frames and wraparounds: ordinary frames let enough UV in at the sides to reduce the benefit, and wraparound styles block light from entering around the frames. Frame shape names such as round or square describe appearance and do not appear in the regulation or in the AAO guidance.
Where each type is used
- Driving and open water: polarized lenses address reflected glare. A single gradient is described as useful for driving; a double gradient is not recommended for it.
- Snow, beach and water sports: double gradient and amber lenses are the types described for these, with the limits in the table above.
- Everyday outdoor use: the UV label is the first thing to read, then the glare and light conditions the lens is built for. Photochromic lenses adjust to changing light but change slowly.
- Clinic, hospital and laboratory: nonprescription sunglasses are defined as protection from bright sunlight, not from workplace hazards. Eye protection against splashes, particles or chemicals is a different product category; see what safety goggles are and face shields vs safety goggles. Eye clinics that stock disposable shades for patients after dilation are covered in the optometry clinic supply checklist.
What to check on the label
- UV blocking: the AAO points to labels stating that the lenses block “99 percent or 100 percent of all UV light”; a label reading “UV absorption up to 400nm” means the same thing.
- Tint is not a UV indicator: color and darkness say nothing about UV blocking, and polarization is unrelated to UV absorption.
- Impact resistance: 21 CFR 801.410 requires eyeglasses and sunglasses to be fitted with impact-resistant lenses. The test in 801.410(d)(2) drops a 5/8-inch steel ball weighing approximately 0.56 ounce from a height of 50 inches, and the lens must not fracture. The regulation allows an exception where a physician or optometrist finds such lenses will not fulfill a patient’s visual requirements and directs the use of other lenses in writing. FDA’s questions-and-answers guidance (September 2010) is nonbinding.
- Prescription lenses: a pair made to correct vision is not “nonprescription sunglasses” under 886.5850, which excludes refractive correction. The migraine-lens case is covered in FL-41 glasses: FDA class and what studies show.
Care and replacement
Care and replacement instructions come from the manufacturer and are supplied with each pair. The federal definition and the AAO guidance cover lens and frame types and UV labelling, not cleaning methods or replacement intervals.
FAQ
Does a dark tint mean UV protection?
No. According to the AAO, color and darkness do not indicate a lens’s ability to block UV light. The label to look for states that the lenses block 99 or 100 percent of UV light.
Do polarized lenses block UV?
Not by being polarized. The AAO says polarization has nothing to do with UV absorption; it reduces reflected glare. The UV label on polarized pairs is read the same way as on any other.
Are sunglasses FDA approved?
Nonprescription sunglasses are classified by FDA as Class I devices under 21 CFR 886.5850 and are exempt from 510(k) premarket notification. They are classified and regulated, not individually approved. They must still meet the impact-resistance requirement of 21 CFR 801.410.
Do mirror-coated lenses block all UV?
Not necessarily. The AAO says the metallic coatings reduce visible light but may not block UV, and full UV protection should not be assumed.
Are wraparound frames different from ordinary frames?
For sunlight protection, yes: the AAO says enough UV rays enter around ordinary frames to reduce the benefit of protective lenses, while wraparound styles block light from entering around the frames.
Sources
- 21 CFR 886.5850, Sunglasses (nonprescription): https://www.ecfr.gov/current/title-21/chapter-I/subchapter-H/part-886/subpart-F/section-886.5850. Checked 2026-10-30.
- 21 CFR 801.410, Use of impact-resistant lenses in eyeglass and sunglass frames: https://www.ecfr.gov/current/title-21/chapter-I/subchapter-H/part-801/subpart-H/section-801.410. Checked 2026-10-30.
- FDA, Impact-Resistant Lenses: Questions and Answers (guidance, September 2010): https://www.fda.gov/regulatory-information/search-fda-guidance-documents/impact-resistant-lenses-questions-and-answers. Checked 2026-10-30.
- American Academy of Ophthalmology, Sunglasses: recommended types: https://aao.org/eye-health/glasses-contacts/sunglasses-recommended-types. Checked 2026-10-30.
