Many customers choose to have their glasses matched discount eyeglasses online, and they have to solve the problem of their prescription.
The term 'degree type' is a bit inaccurate, it should be called refractive error. But this is relatively easy to understand. Generally, what we commonly see is myopia. But there is still farsightedness, mixed dispersion, and so on. Hyperopia is more common in children.
Why do we talk about the types of degrees? It's because we need to distinguish between hyperopia and myopia. To clarify the accurate way of writing degrees.
At first glance, the cheapest eyeglasses online data is quite comprehensive, including the astigmatism axis of the spherical lens and cylindrical lens, except for the distance between the pupils. But it's this'+'sign that's confusing. The customer confirmed that he is nearsighted, not farsighted. But what if this "+" represents a positive mirror in the sense of glasses fitting? Because a degree has different ways of expression.
S stands for spherical mirror, commonly known as myopia or hyperopia. C stands for prism, commonly known as astigmatism. This lens is usually written as -3.50/-0.50, which means myopia at -3.50 degrees and astigmatism at -0.50 degrees. But it can also be written as -4.00/+0.50 Different representations, the same degree.
The image provided by the customer cannot determine the meaning of the "+" sign in front of astigmatism. There are two possible degrees for this degree: A and B. The difference is quite significant.
The prescription is incorrect, no matter how expensive the lenses are, they are useless. Most machines nowadays are very accurate, and adjustments are usually made based on this foundation. So now optometry for eyeglass online is very simple.
