Went to eye doctor because i thought i may have seen a flashing light in my peripheal for a split second. he found nothing wrong. is photopsia hard to miss when you experience them?

There in nothing wro: There is nothing wrong with you, as you did see an eye doctor photophobia is not hard to miss when you experience it.

Possibly from medicines: Photopsia can indicate a very serious problem with the eyes, but these kinds of flashes have also been known to be associated with migraine headaches and also to sometimes occur with serotonin-enhancing medications. Sertraline increases serotonin, and all three of your medications can cause headache's. Suggest talking with the prescriber of your medicines. Ref: http://en.M.Wikipedia.Org/wiki/photopsia.

Yes. Often.: Clinicians cannot see your flashes. Only you can see those. We can however, explain flashes on the basis of subtle changes in the vitreous gel and signs of traction on the retina. Most unilateral flashes are a result of vitreous traction - also not always evident on exam. So, if exam is normal and no (retinal) defects were found, i wouldn't worry. Inform your doctor if you have any rd signs.

Easy to see: Photopsias are light flashes that occur when the retina is stimulated in any way: e.g. pressure, fluids swirling inside the eye, changes in the character of the vitreous, etc. Most are benign but continued flashing might be a clue to retinal detachment. This would be rare at your age although you will easily notice photopsias when they occur.