My situation is worse than your daughter's, and although it's not something I'm happy about, and it's sometimes a pain in the neck, I wouldn't say it's affected my life significantly negatively, either. There are far worse disabilities to have.
I am a -6 diopter in one eye, have uncorrectable dim vision in the other, and have double vision as well. The myopia and double vision are mostly correctable, so I can drive. I cannot see details unless something is very close to my face.
I wear hard contacts (rigid gas-permeable) because I haven't been able to find a soft contact that lets enough oxygen through -- I have dry eyes so this is a serious thing. My vision would be best with soft contacts because I have astigmatism, because soft contacts form to the eye, but it's okay with hard contacts. It's far better with the contacts than with glasses, because the thicker the lens, and the farther away from the cornea the lens sits, the more distorted your vision will be.
Your doctor can give you lenses that will give you an idea of what your daughter is seeing. This is very close to what I see with my myopic eye: http://www.sparklingplanet.org/image...livingroom.jpg
(As you can see it's not a simple blurring, there's some ghosting and starbursting) Original photo: http://www.sparklingplanet.org/image...ingroom600.jpg
|BTW, if I understand correctly, visual acuity cannot be determined until the child is old enough to describe what they see since two people with the same lens strength may have 2 very different acuities depending on how well they can each compensate for the impairment. Is that right?
I'm not sure what you're saying here, sorry.
There are a number of variables that determine acuity, and currently there is no machine that can perfectly account for them all, so subjective experience is going to be the best gauge. But the machines can get pretty close.
ETA: my vision stopped getting worse when I was in my late teens, and has since then only needed minimal fine tuning from time to time. Also, I wanted to say that a benefit of being severely myopic is that without my contact in I can see VERY UP CLOSE, which is helpful when removing slivers!