Depends mostly on the wavelength. UV of ~350-400nm Will pass through most plastics. But less than ~300nm would be absorbed. Here's some graphs of the transmission. http://usa.dupontteijinfilms.com/wp-content/uploads/2017/01/Mylar_Optical_Properties.pdf. Do Plane Windows Block UV Rays? Camp said that plane windows can prevent some UV rays like UVB rays (which have a shorter wavelength) from leaking through. Aircraft windows are made of thick plexiglass, such as polycarbonate or acrylic plastics, that can filter out a decent amount of UVB light. Help maintain eye health. Improve sleep. Reduce eye strain. The amount of blue light that comes from these digital devices is weak compared to sun exposure, and many experts are skeptical as to 2. Park in Shaded Areas. Another straightforward way to protect your car from UV rays is to park it in a shaded area. Parking under a tree or in a garage can reduce the amount of direct sunlight that reaches your car, preventing the paint, plastic, and rubber components from fading and cracking. Solar control window film only blocks UV rays – not the red and blue rays that your plants need to grow and flower. And some plants will actually do better with window tints and films, such as those that require less light — which typically have dark green leaves. IIRC the eye doc told me that UV rays are what cause the lenses to darken. EDIT>>>> How Do Photo Gray Lenses Work? In the glass or plastic used to make the glasses lens, silver halide is mixed in evenly. This substance is sensitive to ultraviolet light, and will darken when exposed to it. The drawback of this method is that thicker parts of a Swimsuits made with UV-protective, chlorine-resistant material (UPF 50+) block at least 98 percent of UV rays. High-UPF swimsuit retailers include: Solartex; Coolibar; Hats. You may notice the color of the paint on your walls or your furniture fading thanks to years of prolonged sunlight exposure. In more serious cases, prolonged UV exposure could lead to burns or possibly cancer. Most UV rays will enter your home through outdated single pane windows. These windows are often builder-grade with low-quality glass. c3xA.