My wife and I use the Latanoprost eye drops for glaucoma. She uses Systane gel drops for the dry eye and I use the Latanoprost every other night to control the dry eye. Many users of glaucoma eye drops seem to think that the dry eye is caused by the eye drops and some research suggests it's the preservative in the eye drops that causes the dry eye. Your doctor may pooh pooh this, but non preservative glaucoma eye drops are available and he may consider having you try them since I'm guessing you did not have the dry eye before you were diagnosed with glaucoma 5 years ago. Or does he think it is simply a coincidence that your eye irritations started when you began taking the glaucoma eye drops? Don't forget that you can always get a second opinion from another doctor recommended by your friends. Two heads are generally better than one. I'd choose a doctor associated with a nationally known institution such as the Mayo Clinic or Johns Hopkins Wilmer eye institute.