If they can do the surgery at a young age, then they will be helping to avoid problems in the future.  I have 2 lazy eyes, never had surgery, but I have to really work hard some times to make sure I am keeping both of them forward to the front.  Imagine a chameleon lizard that has independant movement of their eyes, and that's me! lol.

clay cook's son has strabismus and I think they had a surgery before age 1. I will put a link to related articles under your question. Please feel free to browse.

my cousin J has had several of these operations on her eyes. Both her eyes turn in. her first was at about 18 months i think as her eye was completely in. she is now 14 and i think has 1 more operation and she is fine. (she has been slack on her phsyio)

I have never had to deal with my child having a operation, but I was there for my GF when her son had to have his plates in his head (the skull had fused too early) and she was ok in the end with it (It brought back memories of her brother)

In the end tell yourself it is best for her.

My niece had the surgery at about 2/1/2 and it worked fantastically for her. She healed really quickly and was up and about almost straight away. her eyes are now perfect and it is a relief to her mum cause they were having so much trouble keeping the patch on her.
I think what you described is what they did to her as well, as hers was also turning in.
It is very very scary, but will be worth it in the end.

We are also patching my son and I don't think he will need surgery but we have met other parents who's child has had to have that surgery and it worked well for them. I have heard the same surgery on an adult is done with the adult awake so that to me makes it seem like it must not bee TOO bad. I know it must be so scary and I would be really worried if it were my child too. You and your child will get through it though and if you are strong for your child they won't be so scared about it themselves also.

I have a friend whose little boy is 3 in November and he has just had this done about a month ago.  Not sure if it is exactly the same type of surgery but it was for the same problem.  He was only in hospital for a day and was back at playgroup a week later.  He is recovering well.  I hope that helps reassure you!

It sounds like you are very lucky that it is being diagnosed and that they have surgery to correct it.  More importantly, they are offering you that surgery, many parents find it difficult to get their children appropriate health care.

In regard to her age, the younger the better, she will bounce back and recover quickly and she will respond the same way you do.  If you treat it as a positive, important, amazing thing, she will be fine, as she experiences the world through your eyes, and trusts you.