In some special cases, such as want to estimate how many degrees of myopia, naked eye vision is about how much, available the following method, in general, the visual acuity table difference of one line, the degree difference of 25-50 degrees, myopia 100 degrees, that is, a difference of about two lines, the estimated naked eye vision in 0.6, of course, the estimate is very inaccurate, and is not recommended to use. Myopia 100 degrees refers to the degree of optometry, and a few points refers to the naked eye vision, there is no constant relationship between the two, that is, myopia 100 degrees must be a few points of naked eye vision. If this is the case, after checking the vision, the doctor may not open the optometry, but directly tell you how many degrees, to go to the glasses, obviously not very scientific, such as the same two 100 degrees of people to check the vision chart, there may be a 0.8, the other 0.6, there are differences between the two. Similarly, two people with 0.6 naked eye vision go to the optometry, one 50 degrees, the other 200 degrees, this situation also has, so there is no reciprocal relationship between the two.