I agree with John, it could be coloboma - I have it myself, although my pupils are circular, they are located at the bottom of the iris, kind of as if a black ball is rolling inside my iris (but not moving).
I'm 33 now and until now I never had glasses. They simply didn't work, or make enough of a difference to be worth the hassle. Don't feel that you've deprived her of anything - my parents say even now that they felt helpless but I know there was simply nothing they could have done anyway.
Since we don't know if your daughter actually has coloboma, I can only answer your question as if she does - but you really do need to see a specialist to be sure. By that I mean the top eye surgeon at your hospital or perhaps higher than that. Most opticians have never seen coloboma except in textbooks. My hospital "one of many" eye doctors took one look at me and referred me to the two specialists, way out of his depth. Even then the specialist said he'd only seen one other patient like me in the last couple of years. Coloboma is very rare, I don't know if anyone knows what causes it (growth defect, but as to why?), and unless someone invents a procedure, it won't get better (sorry to be blunt but that's the way it is).
Incidentally, if you have ever heard of Madeleine McCann, a British girl abducted and so far not found, she has coloboma in one eye which looks like a tear drop. See http://news.bbc.co.uk/1/hi/magazine/7256513.stm for some brief details.
As for me, I had congenital cataracts (ie born with them) in both eyes. My right eye has a hole in the vision in that I can only see around what I'm looking at, not the object itself. Reading is virtually impossible. With my left eye I can do most things including drive. I recently saw the doctor because of "floaters" in my left eye which, although wasn't what I feared (signs of retinal detachment), did prompt the doctor to suggest cataract surgery which I've now had on the right (bad) eye - a practice run because of other complications. He will do my "good" eye in a couple of months.
Long term prognosis? 30 years ago the doctors said I would probably be blind. 30 years later I'm not. In fact I'm not sure my vision has changed much, if at all. And now they say it probably won't change except as normal as the normal ageing process.
I can sort of understand your position, from what my parents have told me about what their concerns were. I've only just joined this forum so I don't know whether you can email me direct but please feel free to do so if you wish. But please see an eye specialist, not just your family doctor/optician.
She should be under the care of a pediatric ophthalmologist Eye MD. Glasses will not help a tear drop shaped pupil. There are different causes of pupil not round one is iris coloboma. The need for glasses is a separate issue. I trained at Emory. Suggest you see a pediatric eye MD at Emory Medical school Dept of Ophthalmology.
JCH MD