For nearsighted people, it is necessary to wear a pair of nearsighted swimming goggles when swimming, but it is not easy to pick the right pair. Two days ago a viewer called the “Curiosity Lab” asked: “I am nearsighted 500 degrees, bought three or four pairs of swimming goggles, either can not see clearly or wear dizziness, is the quality of swimming goggles, or did not choose the right it?” Now, myopic swimming goggles are mainly sold in sporting goods and on the Internet, basically finished products, lenses common degree from 100 degrees, to 50 degrees as a unit increment, to 1000 degrees are available. The Curiosity Lab first bought seven pairs of myopic swimming goggles from the Internet, ranging from 150 degrees to 800 degrees, with a minimum price of 22 yuan and a maximum price of 268 yuan, and then sent them to Zhejiang Eye Hospital to do a degree test first. As a result, four pairs of swimming goggles diopter in line with the label, there are three pairs of deviations: one pair of swimming goggles labeled 150 degrees, the left lens detected 170 degrees; a pair of swimming goggles labeled 500 degrees, the left and right lenses detected 525 degrees; a pair of swimming goggles labeled 700 degrees, the left and right lenses measured only 675 degrees. ”The deviation is not particularly large, basically within 25 degrees or 50 degrees. For swimming glasses, this error is still acceptable.” Myopic swimming goggles are uncomfortable to wear, mostly because of incorrect degree selection. “Water refractive index is higher than air, so when choosing myopic swimming goggles, the degree must be lower than the usual frame glasses worn.” There is no national standard for myopic swimming goggles, so how to choose the right goggles according to the degree of myopia? There is a formula to learn from – the degree of swimming goggles, equal to the degree of myopia plus half of the degree of astigmatism, and then subtract 50 degrees to 100 degrees. For example, if the caller has 500 degrees of myopia and 0 degrees of astigmatism, then the appropriate myopic swim goggles for him are 400 degrees to 450 degrees. For two eyes with different degrees of myopia, in the choice of myopic swimming goggles, to adhere to the principle of “on the low not on the high”. If the degree of selection is high, things will happen some distortion distortion, will cause dizziness and nausea. Some people will use contact lenses plus flat swimming goggles to replace myopic swimming goggles for convenience. This method can cause damage to the eyes. “Impurities in the water may be adsorbed in the contact lens, which is equivalent to wearing a bacterial nutrient bed in swimming.”