What is the necessary data to prepare before eyeglass online lens matching, how to obtain it, and what should be noted?

What are the optometry data included? include:

1) The spherical degree of the left and right eyes (i.e. the degree of myopia for most people and the degree of hyperopia for a small number of people)

2) Column mirror degree (also known as astigmatism degree)

3) Astigmatic axis position

4) Pupillary distance (also known as PD, note that there may be different distances between the left and right pupils)

5) Monocular corrected vision (try to achieve consistent corrected vision between both eyes)

If there is no astigmatism, only the degree of myopia and pupillary distance. Correct vision. 'Pupil height' does not belong to the category of optometry data.

Put on your old glasses! The same principle applies to bringing medical records when seeking medical treatment. This is crucial. You can learn about the original degree, astigmatism axis, pupillary distance, wearing time, clarity, and subjective perception. Only by fully considering the old eyeglasses can the most suitable eyeglasses online cheap data be provided.

On the surface, let's first look at the most basic optometry equipment: computer optometry instrument+bull's eye+projector, which is the most basic hardware device to ensure accurate optometry.

Balance between both eyes is also necessary, and after correction, the vision should be as consistent as possible between both eyes. After basically determining the degree, ensure that it is "clear" and "comfortable", and write down the optometry data (do not send computer optometry forms).

It is necessary to compare multiple data with the previous optometry data. Finally, determine which eyeglasses online cheap data is more reasonable to use. The process of optometry itself is a constantly guessing and verifying process. Finally, I will help you determine which data from multiple sources is the most suitable.