If you don't have astigmatism, this column will be left blank. The ADD column of your glasses prescription indicates any additional lens power your eyes require to read comfortably. It can be ...

1 Over 4 billion people globally use prescription lenses ... spherical corrective lenses. With astigmatism, the required optical compensation varies across different axes, necessitating a ...

You may be given glasses to correct astigmatism; if you already have glasses, a correction can be made to the lenses' ...