Side effects that have been observed in persons that have been treated with generic Alphagan drops include dry eyes, red eyes, irritation of the eyes, headache, blurred vision, a feeling of a foreign body in the eye, and drowsiness. Less common side effects are corneal staining, increased susceptibility to light, eyelid redness, eye pain, tearing, and eyelid swelling. Consult a local physician if you experience any of these side effects after you buy Alphagan online.