Rubbing eyes - don't know why!

[HogMoonay]

My 5yo DS started rubbing his eyes on Christams Day. He was coming down with a virus and was very tired but got over it after a few days (although was not eating, excessively tired and achey)but the eye rubbing hasn't stopped.

He doesn't seem to have conjunctivitus (no gunk, redness or puffiness) so I assumed maybe just tired and dry from being ill. I put Optrex drops in yesterday but he went nuts saying how much it stung. Anybody got any advice?

Is he drinking enough? My son does this, I even took him to get his eyes tested incase he needed glasses, the optician said it was probably because he wasn't drinking enough, the ex-mil also does this though so who knows. It did stop once he started drinking more though so this may help.

Strangely he has been drinking lots - he normally drinks next to nothing but has been gulping it back. Perhaps he's dehydrated hence being thirsty?

Thanks for the tip, I will encourage more drinking and see if it helps.