Does medicare cover vision or am i reading this wrong?

read the medicare website 3 times and I still don't fully understand what im looking at. something about medically necessary eye exams being covered but routine ones not being covered and i don't know which category i fall into. i just need to see. is that medically necessary or not? retired last spring and my husband keeps saying just go but he has perfect vision and has never thought about this in his life so hes not helpful. i feel like missed a step somewhere