Ask an Eye Doctor and Get an Answer ASAP
Since how long have the symptoms been there?
Does he wear contact lenses?
Does he have a known history of sinusitis?
One of the most common sites for lodgement o foreign body in the eye is the sub tarsal sulcus. It is the inner surface of the upper eyelid. It can only be seen on everting the uppr eyelid. Tiny speck of dirt or dust can get stuck here and does not dislodge with eyewash. It needs to be removed manually with a cotton bud.
If he does not find any speck on everting the eyelid then it is better to get he eye xamined by an ophthalmologist for a closer look and evaluation under the slit lamp.