I'm going to give you the short version. Flashes can be a symptom of a retinal tear, retinal detachment or a vitreous detachment, so it is extremely important that you see an ophthalmologist asap to have an evaluation for that. If everything looks totally normal then you may have some obscure situation like pressure phosphenes or other conditions that rarely have any dangerous implications. Again, see an ophthalmologist for a complete evalauation right away.
Generally, flashes of light are something you want to have an opthalmologist check out. It could be insignificant, but you sort of indicate this started rather suddenly just two years ago (not something you've had all your life, right?). I'd make an appoint with a doc.
The Content on this Site is presented in a summary fashion, and is intended to be used for educational and entertainment purposes only. It is not intended to be and should not be interpreted as medical advice or a diagnosis of any health or fitness problem, condition or disease; or a recommendation for a specific test, doctor, care provider, procedure, treatment plan, product, or course of action. Med Help International, Inc. is not a medical or healthcare provider and your use of this Site does not create a doctor / patient relationship. We disclaim all responsibility for the professional qualifications and licensing of, and services provided by, any physician or other health providers posting on or otherwise referred to on this Site and/or any Third Party Site. Never disregard the medical advice of your physician or health professional, or delay in seeking such advice, because of something you read on this Site. We offer this Site AS IS and without any warranties. By using this Site you agree to the following Terms and Conditions. If you think you may have a medical emergency, call your physician or 911 immediately.