I have been experiencing light flashes in my eye for quite some time. And called the doctor about it. The last time I saw the doctor was back in March. So, I called the doctor to ask about them, and the nurse told me to come in same day. When they work one in same day, it's something potentially bad. I arrived early, and while sitting in the waiting room, a couple left the exam room, and the nurse got on the phone with our local retina expert. She set them up for later that afternoon. When they left, she said the patient had had flashes yesterday, and was blind in one eye today.
So, if you have light flashes, or they're getting more frequent, call today. Because it could mean a detached or detaching retina.