Hi. I'm online and happy to answer your question today.
You are correct. The most common cause for your symptoms is an ocular migraine.
A typical migraine headache starts with shimmering lights, often times they surround a blurry area or have dots or jaggedly lines associated with them. They tend to progressively increase in intensity and sometimes march across the visual field causing difficulty with reading. Many times this is then accompanied by nausea, irritability, sensitivity to bright lights and/or loud noises. After the onset of the lights (called scintillating scotomas), the headache typically starts and the light show tends to progressively go away.
Many people can have this migraine phenomenon without the headache; it is called an acephalgic migraine. Some people even start having these late in life, or may have had a few much earlier in life that behaved differently and haven't had any for decades and then begin to have them; this is not uncommon. A family history of migraines is often present as well.
This is nothing to worry about. It is not a sign of a more serious underlying condition, brain tumor or anything like that. If the episodes become so frequent that they are bothersome there are medicines that can be used to decrease their frequency or stop an episode once it has started.
These "light shows" usually last less then an hour.
Does this make sense to you?
I am happy to be able to help you today. If you would be so kind, please help me get credit for my efforts in answering your questions and press the ACCEPT button for this encounter. I would also be happy to continue to answer any more questions you have until we have resolved your concern.
And, now, the obligatory word from our sponsors: :o)
I hope that this information was helpful for you. Please, allow me get credit for my time and effort in assisting you and press the ACCEPT button for this assist. I will be glad to answer additional questions until you are satisfied. Thank you very much. Positive Feedback and/or Bonus is welcomed and appreciated.
I see that you are offline. We can use the Q&A system to 'text message' each other. An email will be sent to each of us every time something is posted to this thread.