I bought a pair of flat glasses. The glasses may not have been processed during processing, so the prism effect appears to be a bit off, so...

Since it is flat light, theoretically speaking, the power is 0, but under normal circumstances, the glasses will have a little power, but according to the national standard, a deviation of 12 degrees (0.12D) is considered It is qualified.

The calculation of prism is P=F*C.

F is the degree, the unit is D, C is the center shift, which is the distance of the optical center shift. The unit is centimeters

That is to say, if it is flat light, that is, F=0.00D, then P must be 0, and there is no triangular prism. If the power is 0.12D, then assume that the mirror moves the optical center by 1 cm , then prism P=0.12*1=0.12, normal human eyes will not be uncomfortable with 0.12 prisms.

If you feel that there is something wrong with your vision, then you can go to an optical shop or hospital to check whether there is something wrong with your glasses. If there is no problem with your glasses, then you have to consider whether there is something wrong with your eyes