What subject do optometrists have to study?

Optometrists: Visual acuity and recommending eyeglasses or lenses, basically vision exam.

Not in depth: Optometrists study eyeglass correction and contact lense fitting. They get a smattering of eye disease and think they know a lot. But only ophthalmologists study these things in depth with approximately 8 more years of study than optometrists. It is best, if you have an eye problem to get an ophthalmologists opinion and evaluation first.