If the degree of preparation is higher than the actual value, it will generally be clearer, but at the same time, the visual deformation will be greater. When the eyeball adapts to this change, it will use the eye muscles to adjust itself. If it is adjusted for a long time, it will not be adjusted. Adaptation will put a burden on the eye and damage your vision. If the degree of preparation is lower than the actual value, although it may not be visible in the distance, the visual deformation is small, and the eyeball is easy to adapt to changes and is not easy to fatigue. However, if you want to look farther and look hard, it will make the eye muscles unable to relax, and eventually cause vision loss. Therefore, matching a pair of appropriate glasses is very important to protect eye health.