We persons usually adjust the size of pupils according to the power of light. The pupils get contrasted when the light is strong and get dilated when weak. However, when the light is too strong for us to adjust the pupils, our eyes would get hurt. Therefore, in summer, sunglasses are well received for their fashionable and aesthetic appearances and shade and radiation proof functions. With sunglasses, sunlight would be shaded and at the meantime, harm from the strong sunlight to eyes would be greatly reduced.
The sunglasses are so popular in summer that many inexpensive sunglasses, ranging from even $1 to $10 dollars, are on sale in some small optical stores. They are fashionable and cute in appearances, however, no package or hang tag is provided, from which one would easily get to know that they are produced by informal factories. However, even though many people know that they are poorly made, they would buy just because that they are cheap! And they hold that they perform the same with high quality sunglasses.
However, the fact is that inexpensive eyeglasses, especially those poorly made ones, are really bad for our eyes. Exports concerned introduce that forged and fake sunglasses are incapable to protect eyes, but instead do harm to eyes. It is known that pupils get constricted when shined by strong sunlight, which would in some degree block harmful rays, like ultraviolet radiations. At this rate, pupils get dilated in dim light. As a result, wearing poorly made sunglasses which are not able to block ultraviolet radiations effectively would let more UV inject into eyes. We could say that it is better for one not to wear any sunglasses than to wear low quality sunglasses. If wearing this kind of sunglasses too often, eyes are possible to get burnt. If severely enough, those damaged cells on retina would not get recovered.
Therefore, one should refrain from seeking small gains at great cost. Anyhow, eyes are precious. Inexpensive eyeglasses no doubt would save you a lot of money, however, do you know that you are saving money at the risk of hurting your eyes. If you do want to find cheap ones, you could shop in online optical stores, because due to the special business practice, a great amount of cost would be saved.