What's the difference between Medical Insurance and a Vision Plan?

Vision Plans (such as VSP and EyeMed): Allow for a patient to receive routine eye exams for glasses and possibly contact lenses. These plans may also give a discount on glasses or contact lens purchases. Vision Plans do not cover any evaluations or testing for eye diseases or medical complaints such as eye irritation, dryness, eye allergies, diabetic evaluations, floating spots in vision, or glaucoma evaluations, to name a few.     Medical Insurance (such as Medicare, Anthem, Optima, etc): Allow for a patient to be evaluated and treated for any medical complaints such as dryness, eye allergies, eye pain, eye redness, etc. Medical Insurance also allows for diagnostic testing and evaluation of eye diseases such as glaucoma, keratoconus, diabetes, macular degeneration, cataracts, and blepharitis, to name a few.  Medical insurances typically do not cover refractions for a glasses prescription or contact lens evaluations, so patients may have to come back under their Vision Plan, or self-p