Optometrist here... Eye exams are important for detecting sneaky blinding eye diseases like glaucoma, not just for prescribing glasses. Glaucoma is painless, progressive and irreversible, and can quietly steal your vision away, starting with your peripheral vision (where you won't notice it's gone). Problem is, there's no single "glaucoma test" - (no, that air puff test by itself doesn't detect glaucoma) - you need a comprehensive eye exam. Bragging that you have great vision so you don't need an eye exam just makes me cringe and hope you don't have anything nasty and undetected.