He may have dry eye ...but please keep in mind that he may have some refractive error as well...means glass number , especially if patients have number ! Now things are open ..with all due precautions get him checked as well if lubricating drops dont help much .

Please try to reduce his screen time especially on the mobile.

Whatever he is able to follow of the given instructions will help. Few instructions: 1. Follow 20-20 rule. After every 20 minutes of any near work say laptops, mobile or reading take a break and focus for 20 seconds at a far away object at least 20 meters away. 2. Frequently blink your eyes while working, if not possible to remind yourself to blink then at least after 30 minutes of your work slowly close your eyes 10 times. 3. Adequate water intake 4. Adequate sleep at least for 7-8 hours 5. Do not rub the eye 6. Use anti reflective coated glasses if you have spectacles 7. Health nutritious diet 8. Cold compress to the eyes 3 times a day (Can dip clean cotton in refrigerator cold water and keep over closed eyes for 30 seconds)