Yes you would have to apply to medical school just like everyone else, which means you have to take the MCAT and score well to be competitive for admission. I think the only advantage you would have in this position is that completing a professional degree shows that you can manage and handle a medical school curriculum as well. However, schools will question your decision of why you are giving up on your profession. If you want to be an ophthalmologist, apply straight to med school - there is absolutely no reason to complete an optometry degree prior to med school. You're looking at 4-5 years of wasted time and money which will add on to 8-10 years of med school education. Another thing to keep in mind is that ophthalmology residency spots are not handed out for free, you will have to perform really well in school to secure yourself a spot in a very competitive residency.