• I have glaucoma in both eyes, which I take medication for. Lately I feel pain in my left eye when I blink, as if something is stuck under the lid. What is that?

My glaucoma is under control with the current medications I'm using: Cosopt and Xalatan eye drops. For 3 days, though, when I blink I feel pain in the left eye as if there is a particle there. The eye is slightly red but it does clear from time to time. What could this be, and are there other drops I can take to help relieve that "something-in-my-eye" feeling?