Any eye bods about - query about long-sight/squint?

[MamOfTwo]

I know there are some knowledgeable eye professionals on here so hoping they see this post...

My DD age 5.5 has been wearing glasses since last October 2015. She is long-sighted and has a left convergent squint in one eye. Her current prescription is 4.5+ in each eye. At our appointment today they said it had increased to 6.5+ but they were going to undercorrect it because of the squint so prescription staying at 4.5+. I think they said 6.5+ would make her eye with squint turn out but don't really understand why this is? Just concerned that her prescription is not as strong as it should be and she can't see properly? We have done patching in past but told not to carry on with that at moment. Is it likely she may surgery to correct the squint? Just feeling confused and guilty that I didn't pick up on her eye problems earlier. I do ask questions at our appointments but find it hard to remember everything they say!

[MamOfTwo]

Wee bump

[underneaththeash]

Its quite difficult to explain. But when you are long sighted the eye has the ability in children to adapt its focus to overcome the longsightedness, but this has a secondary effect of making the eye converge at the same time. Its called the accommodative/convergence effect. In some people this effect is very pronounced and they end up with a squint.

In some children the squint is fully corrected when they wear there glasses, but giving them stronger glasses can make the squint go the other way.

Having the prescription +2D lower than the actual prescription will not be detrimental to her sight at all. It would be if she was short-sighted, but in long sighted people they can do this accomodation thing that allows them to adapt their eye lens shape in order to see clearly.

The patching thing is different and is done to force the bad eye to see more letters on the chart, rather than to stop the eye from squinting. If the squinting eye can already see the same amount of letters as the good eye (or if there has been no improvement in the amount of letters the bad eye is able to read on the chart for several months), there is no point in continuing to patch.

Its unlikely that she will need to have surgery if the squint is fully straightened when she wears glasses.

I hope that made sense!

[MamOfTwo]

Thank you so much for taking the time to answer. You explained that really well and it is a great help, thank you!