An Optometrist visit is more than just corrective lenses, its about checking the health of the eyes and looking for potential problems like glacouma, retinal detachment, macular degeneration, cataracts etc. I will be going every year just for that alone.
But you are going to the wrong place. Optometrists are not MD's. They are not permitted to diagnose or treat disease; like any competent layman, they can refer you to somebody who is an actual doctor. That would be an Ophthalmologist.
If you need a refraction, go to an Optometrist. For the other things, you should be going to an Ophthalmologist, or better yet, an Ophthalmologist who is also an Optometrist, or who does refractions. Ophthalmic exams usually include a refraction, and (at least my) Ophthalmologist will give you the script for the same price as the non-doctor.