Thank you for your additional information. Here is what I suggest because it would be irresponsible not to. Get your vision checked first. Perhaps just get a 'general check up' and mention that your peripheral vision is bothering you. It is possible to get a check up without saying "I am seeing ancient symbols and words". Just mention that you are seeing black and white flashes that you cannot really make out. I know it is not full disclosure but it is better than not investigating this at all. If all of that comes up clear, and you are not, or have not, suffered any neurological symptoms that suggest a stroke either, then we must look at what I actually think this probably is:

An ability that has always laid dormant within you is coming to the fore now. More and more people are coming out and asking if they are crazy, because they are seeing or hearing things that, as young children, we are all taught we cannot actually see. By the time we reach adulthood many people can't 'see' or 'hear' any more and, of those who still do, most remain silent because they have learned that ridicule for being honest about their experiences is swift, or a spontaneous diagnosis of mental ill health is doled out if they seek medical aid.

At the time of writing it is hard to separate the timing of this experience with your decision to look up an old love so it is difficult to know if she is somehow connected, or if the timing really was coincidental. I saw the photograph of her and yes, she is a trouble maker.

However, first things first. Please get your mundane physical health looked at first. If a medical cause can not be found, then it really is time to work on managing and mastering this gift of yours. Please also take a note of everything you are doing before, during, and after you experience this. Write it down if you need to, if it is possible that you will forget. See if you can find a pattern here. Does this happen when you listen to music? When you are hungry? Thirsty? Tired? Look at those kinds of things too and write them all down.

I have now made my email address visible on my profile so, if you would be more comfortable writing to me privately, you are welcome to send me an email.