If you see light flashes in corner of eye, especially for no obvious reason, this could be a red flag, check https://myvisioncare.org/blog/....seeing-flashing-ligh . Flashes of light can also be associated with conditions such as post-concussion syndrome or migraine but in either case, it is worth consulting an ophthalmologist. Read this in-depth piece so you can work out what causes may be behind this symptom and what to do.