Car window glass can block some UV light and IR radiation, but the level of protection depends on the type of glass and its thickness. Ordinary glass blocks most UVB radiation but allows a significant amount of UVA radiation to pass through. Most car window glass is made from tempered glass, which is designed to be shatter-resistant and can block some UV radiation. However, it is not very effective at blocking IR radiation, which is why car interiors can get quite hot on sunny days. 

Exposure to UV-light can have both beneficial and harmful effects, and it is important to protect oneself from overexposure through the use of sunscreen, protective clothing, and avoiding direct sunlight during peak hours.

Window tint film works by blocking a portion of the incoming light that passes through a window. This includes both UV radiation and IR radiation.

Most window tint films have special additives that help to absorb or reflect UV radiation, which can help protect people and objects from the harmful effects of prolonged exposure to UV light. This includes reducing the risk of skin damage, fading of fabrics and degradation of other materials.

In addition, window tint film can also block a significant portion of IR radiation, which is responsible for much of the heat that enters a building through its windows. By blocking IR radiation, the film can help to reduce the amount of heat that enters the car, leading to a cooler and more comfortable environment. This can also help to reduce the load on air conditioning systems, leading to energy savings.

Overall, window tint film provides a simple and effective way to protect against both UV radiation and IR radiation, while also providing other benefits such as increased privacy and reduced glare.