Yes, keep looking for a specific cause, but as for drops, don't be fobbed off with some notion you can apply them say, 4 times a day. When things are bad, it's every few minutes.
Some people are not tolerant to hypromellose. I can't use it. But I can use Snotears. A coupe of quid buys a tiny bottle which lasts much longer than you'd think.
The little white and black box on the right has been my friend for years, though once under control, I don't use it for months at a time. To this day, I use a full military gas mask when using an angle grinder on brickwork etc.!
Sno tears Eye drops 10ml
I thought I was going to have to give up working on my house. The pain was extraordinary.
Hypromellose: Uses, Side Effects, Interactions, Pictures, Warnings & Dosing
Cause. Since I love doing building work, I had a long hard think about what to do. I dug around for an old pipette, and hooked it up to a bit of rubber pipe. The professional smooth tip I used to massage around the outlet of the tear gland - while sucking on the pipe. No one believes me, but I noticed an immediate and marked improvement. Not very good science, but who knows?