The processing of discount prescription glasses lenses has become more personalized. Often, many consumers find a strange phenomenon when they receive customized lenses from certain brands, which is that the packaging bags of the lenses are labeled with strange degrees that are different from the prescription they ordered.

Why is that? Is this a mystery or is there something suspicious? In summary, discount prescription glasses lenses are designed for the use of the wearer's eyes, not for the measurement of focal length.

Why do we need to wear optimization? We temporarily assume that during the subjective refraction process, you have achieved the most comfortable wearing state of the lenses. At this point, whether using a subjective refractometer or a test stand, we believe that the relative position between the lens and the human eye is "standard".

The lens is perpendicular to the line of sight, and the distance between the human eye and the back surface of the lens is fixed. The human eye only sees things from the center, and the periphery is appropriately abandoned. The lens itself is composed of multiple standard lenses combined.

In reality, people wearing glasses vary greatly due to differences in face shape and frame selection. When the lens is not in a "vertical" position in front of the eye, or when the eye uses the edge of the lens to see objects, some optical correction effects different from the "measurement prescription" will be introduced, causing blurred vision.

At the same time, the discount prescription glasses wearer's demand is generally to have a clear field of view as large as possible, with only clear lenses in the middle, so that we only like to see things from a small range and have fewer opportunities for eye movement.