Ultraviolet light can pass through glass, but the amount and type of UV (eg UVA, UVB etc) transmitted depends on the type and thickness of the glass, any coatings and laminates. "UVB rays, the primary sunburn ray, are largely blocked by glass; but more than 50 percent of UVA rays, the main cause of premature skin aging, can penetrate glass. (Both UVA and UVB rays contribute to the development of skin cancer.) If you’re anywhere within several feet of the window, the rays will reach you." source This horizontally reflected light is concentrated and can cause problems with glare, which can be quite disabling. Polarized lenses are treated with a coating that absorbs visible light. The chemical is applied in a sort of vertical stripe pattern. As a result, some vertical light can pass through, but horizontal light is blocked. The longest wavelengths are UVA (315–400 nm) and UVB (280–315 nm), which are found in ordinary sunlight. These are the rays that can cause sunburn if one stays outside too long without protection. UVA and UVB light rays have limited germ-killing ability because viruses and bacteria have had millions of years to adapt to them. Place 3-5 UV-sensitive beads in two small plastic bags. These beads will turn color in the presence of UV light. The higher the intensity of UV light the stronger the color change. Make two bags: one labeled “Control” and one labeled “Experiment”. Record the color of the beads when exposed to indoor light (lighting in the lab). . The change in the plastic's composition is evident in the laboratory, but "visually, it may not appear to have changed much during the process". The rate of degradation is light intensity-dependent, but under the team's laboratory conditions the polymer chain lengths degraded to a quarter of their original length after 30 days of exposure. Click to expand UVC is filtered out by the Ozone layer, UVB cannot penetrate through glass, unless it is glass especially designed for the cause, such as the glass in Reptiles tubes and globes. As mentioned before in past threads, UVC is actually quite dangerous for your Reptiles as it can damage retina's and cause cell damage. Myth #3: Sun can’t penetrate through windows. Reality: Glass filters out only one kind of radiation – UVB rays. But UVA rays, which penetrate deeper, can still get through. That’s why many With the right material (lead) or with the right thickness for any material you are able to capture X-rays inside the material. On the other hand, you are able to transmit visible light even through metal. It's all about thickness. Gold or aluminum can be made so thin that light can pass through it. The earth’s ozone layer prevents some UVB rays from reaching the earth’s surface. However, it does not stop all UVB rays, which can penetrate the skin deeper than UVA rays. Luckily UVB rays cannot pass through glass, so you are protected from UVB rays when in the car or at home. Sunscreen of SPF 30 or greater also will deflect UVB rays. UVC

can uvb pass through plastic