The Answer Is Clear: While state laws vary about darker tinted windows, almost every state allows clear window film that can block 99 percent of ultraviolet (UV) light in your car. Afriandi / Getty Images
Q: I’m super-sensitive to the sun and have had multiple skin cancers. Can I get a medical exemption to allow window film or tint to my car windows to help protect me from more sun damage?
Lisa Winckler: Before I answer that, let me explain that most modern car windshields are laminated, so they already block almost all UV rays. However, most side and rear windows and sunroofs block only UVB rays, leaving skin exposed to UVA rays. UVB rays are the ones that mainly burn skin, while UVA rays are responsible for tanning, skin aging and some burning, too. Both types can increase your risk of skin damage that can lead to skin cancer.
You may not even need an exemption if you opt to add transparent UV-blocking window film on non-windshield glass. Almost every state allows the clear film, which can block 99 percent of UV light. While it may seem counterintuitive, darker tints do not protect against UV rays any better than clear UV-protective film does.
Tinted film is helpful if you’re also looking for protection from visible light (which can cause skin issues such as hyperpigmentation and can also generate free radicals that may lead to DNA damage in skin cells). Only a few states require an exemption to add any degree of tint to your front driver- and passenger-side windows, while sunroofs are generally fair game with no rules around tinting.
Tinted glass also helps protect against heat and glare. If you want to tint your windows, state rules vary by window location (front side windows versus back seat windows) and the darkness of the tint (measured by the percent of light that passes through). The laws in many sunny Southern states, for example, have evolved to strike a good balance between safety and skin and glare protection. They tend to allow for the darkest tints on front side windows, allowing as little as 25 to 50 percent of visible light to pass through. Some even let you go darker with a medical exemption. On the other end of the spectrum, some states may require an exemption for film that allows less than 70 percent of visible light through. Other states fall somewhere in between, and only some allow for medical exemptions to go darker.
Tint rules are stricter for windshields and, again, differ by state. Some states see dark tints as a safety issue, especially while driving at night. So you may need an exemption, or tints on windshields may not even be allowed.
My advice: Search for your state’s rules at the International Window Film Association website, iwfa.com. Or, before purchasing, confirm your state’s laws with the DMV or other state government website.
Bottom line: If you spend a lot of time in the car or drive someone at risk, it can be worth the effort to get an exemption for tinted UV-protective film. You might also consider installing film on windows in your home if you sit indoors in the sun or just to keep the sunlight from fading upholstery, artwork and other materials. To ensure optimal protection, look for films or tints marketed specifically as “UV” or “solar” and those that have earned The Skin Cancer Foundation’s Seal of Recommendation. Find the list at SkinCancer.org/recommended-products. — Interview by Beth Janes O’Keefe
ABOUT THE EXPERT:
Lisa Winckler, a technical consultant for the International Window Film Association, has more than 35 years of experience working in the window-film industry. She retired from Eastman Chemical Company in 2021 as director, global product management and industry affairs for the performance films business. Since 2023, she has been working with The Skin Cancer Foundation to help extend the adoption of UV protection to include window film.
