Does using iPhones ruin your eyesight?

I keep hearing that using your iPhone too much will ruin your eyesight but I also hear from other people that it doesn't cause any permanent damage so I'm quite confused please give me some proof that it damages your eyesight or doesn't

Never heard that

  • Will using a knockoff iphone charging wall adapter ruin my iphone? I know that knockoff iphone chargers are bad for your iphone, but will a knock off wall adapter have any effect or harm the iphone?
  • When you sync your iphone to your computer does it copy everything onto your pc? I have broke my iphone to the point where it is un repairable, i only sync my iphone the other day to my pc does this mean everything what was on my iphone was copied and saved to it? Or have i lost everything?
  • How to make my eyesight more stronger? I've been on my apple iphone a lot even on low brightness but it seems to have ruined my vision when it comes to looking at letters and patterns far away so I have to kind of squint to see clearly I'm cutting my time off it is there anything else I can do
  • How to correct my eyesight without glasses? I have an iPhone 5s and recently I've noticed I've been on it quite a lot and my friend told me IIm developing a squint or a lazy eye when I was a little baby I also had a lazy eye and my vision has become terrible because wen I look at letters it becomes 3D more like and I don't want glasses do I stay off my phone?