Hello,
It is probably because of dryness or some allergy.
Start using E/d Genteal 4 times/d .
If redness or frequent rubbing is there , needs eye clinic visit to rule out allergy.
Next Steps
Avoid frequent rubbing of his eyes. Hand hygiene is important too.
cold compression twice a day will relieve itching till you are able to visit eye hospital.
Health Tips
younger child will not tell about vision, need to check refraction as a part of routine checkup. visiting eye clinic would be best for now.