Flashes in front of the eyes can be a sign of a serious eye problem. As you have already pointed out, this can be a sign of a detached retina, especially if you are older, have bad near sighted vision, or have other medical problems. Other signs that might accompany a detached retina would be blurry vision, a shadow or curtain across the vision, or floaters. If you have any of these signs, this could be a medical eye emergency and you would need to see your eye doctor
Because there are other conditions that could cause these symptoms (for example, migraines are often associated with flashing lights), the best first step would be to have a general eye examination. In other words, it is not necessary to have a retinal surgery
consultation until it is determined that you do indeed have a retinal tear, hole, or detachment. Your eye doctor will be able to dilate your eyes with special medication and then take a good look inside at the entire surface of your retina, quickly determining whether this is the cause of your symptoms.
At that point, if it turns out you do have a retinal tear, then you will need to think about surgery.