Excess of everything is bad.
If eyes are weak, go to the eye doctor & get it checked. This is very alarming. Why are all fed up, I do not know. To get the treatment for the kids, it is parents’ responsibility.
Inshallah you will be okay. Do not worry. Give pauses between readings.
Give some rest to your eyes until they get alright.
Pray 5 times & read Quran daily & pray for yourself.