For myopic people, wearing a nearsighted goggle while swimming is necessary. It is not easy to pick a suitable one. Two days ago, a friend asked: "I have 500 myopia, bought 3 or 4 goggles, is not clear or wearing dizziness, there is a problem with the quality of swimming glasses, or did not choose right?"
Currently, myopic swim goggles are mainly sold on sporting goods and networks. Basically, they are finished products. Lens commonness starts from 100 degrees, and is incremented by 50 degrees to 1000 degrees. First, buy 7 pairs of nearsighted swimming goggles from the Internet, the degree from 150 degrees to 800 degrees, the lowest price is 22 yuan, the highest is 268 yuan, and then send them to the eye hospital to do a degree test.
As a result, the refraction of the four swimming goggles was in line with the label, and there were three pairs of deviations: one was a 150 degree goggle, the left lens was 170 degrees, and the other was a 500 degree goggle. There are 525 degrees out; a pair of swimming goggles marked 700 degrees, the measured degree of the left and right lenses is only 675 degrees.
"The deviation is not particularly large. Basically it is within 25 degrees or 50 degrees. For swimming goggles, this error is still acceptable." Deputy director of the Optometry Clinic of the Eye Hospital said that myopia goggles are uncomfortable to wear. Most of it was caused by incorrect selection of the degree. “The refractive index of water is higher than air, so when you choose nearsightedness goggles, the degree must be lower than the glasses you normally wear.”
At present, there is no national standard for myopia goggles. How do you choose the right goggles based on the degree of myopia? The doctor said that there is a formula that can be used for reference - the degree of swimming goggles, which is equal to half the degree of myopia plus astigmatism, minus 50 to 100 degrees. For example, if you are 500 degrees myopic and 0 degrees astigmatism, then myopic goggles for you are 400 degrees to 450 degrees.
For the two eyes myopia is not the same, in the selection of myopic goggles, we must adhere to the "on the low is not high" principle. If the number is chosen high, things will be distorted and deformed, causing dizziness and nausea.
For the sake of convenience, some people use contact lenses and flat light swimming goggles instead of nearsighted swimming goggles. The doctor said that this method can cause damage to the eyes. "The impurities in the water may be absorbed in contact lenses, which is equivalent to wearing a bacterial nutrition bed to swim."