Eye Pain

I have episodes of pain in my right eye. Two or three years ago, I had a narrow angle Glaucoma attack and I had a laser treatment on both eyes. I see the Ophthamologist every 6 months. I was put on Timoptic Drops with one drop in each eye at bedtime. Apporximately 1 1/2 to 2 years ago, I started seeing large colored balls and different shapes when I would close my right eye. I went to my doctor and he referred me to a Retina Specialist.  He diagnosed a bubble on my retina.  After going to him for approximately 3 or 4 times, the bubble dissolved and I was no longer seeing those things.  I have mild cataracts on both eyes and I am a Diabetic. Could the pain that I have intermittenly in my right eye be from the cataracts, pressure in my eye or could it be caused by dry eyes?  I appreciate any information on this problem.  Thank you.