the sun is the strongest

Sunglasses played an important role, from harmful ultraviolet potential, protect your eyes. Energy in the form of the invisible in the form of radiation, which can damage your eyes, if they were excessive exposure. But the question is, how much protection I need? Or, what time should I wear sunglasses?
The decision whether a particular situation requires the use of sunglasses in the environment, you are in, one of the major determinants and surprising, ultraviolet radiation in the snow, and on the beach, the road and water, more green environment. We often think of a park is some of the most dangerous ultraviolet radiation condition at noon. But in fact, in the reflection of your surroundings, snow and water, provide some of the most dangerous situation. This is because in this case, the amount of ultraviolet light is not easily absorbed by the body you around the green, but fell to the ground, is reflected back, for your eyes. This means, you must close your eyes from ultraviolet lamp above and below.
Another dangerous situations, you should always be careful to wear sunglasses, is when you're in high altitude area. UV rays are filtered out, in the atmosphere. This basically means that the gas filter out ultraviolet you trapped between the gravity of the earth and sun pull, before it reaches your eyes. However, at high altitude, the filtration gas concentration, as well as their thickness, significantly reduced. As a result, the light is stronger, therefore, the presence of UV, at higher altitudes much.
The time of day, of course, also decided to UV the biggest risk factor. Directly from the sun's ultraviolet radiation damage. Therefore, it seems to be obviously, UV exposure is the largest, when the sun is the strongest, at 10 a.m. and 4 p.m. time between. In the time of ultraviolet ray is more direct, so their influence on your eyes is significantly stronger. Therefore, the key is to take the necessary preventive measures in this period, wear sunglasses when outside.