Few things...
I am 34 and in my second year of optometry school. No real problems there.
If you are really worried about debt/money, consider using the military optometry scholarships. I was in the military for 9 years prior to this and am using a scholarship now. They pay 100% tuition, plus 2,000/month stipend, plus the thousands of dollars in equipment. The military may or may not be right for you, but it is a good work environment for most people.
Even if you graduate in your mid-30's, you can still practice for 20 years at least.
If you are a woman worried about children, there are a few women in my school who have children and you have actually given birth during school. It's a real challenge, but can be done.
P.S. I'm not the one giving birth, but have two children of my own...🙂