Hi,
I worried a lot when this first happened to me a few years back. To be sure we're on the same page, I would describe the sensation as the eyeball itself pulsing with each heartbeat. It is disturbing even if you are familiar with it. I've had eyelid twitches in the past and they're no problem.
I have severe neck problems, ie: arthritis and some fusing of a few disks. This causes a lot of tenseness in the muscles making it difficult to turn my head right and left. If I turn my head a certain way, it must cut off the circulation because I'll get really dizzy. It also happens when I'm sitting at the computer holding my head in the same position for a long time. I just have to turn my head back and forth to release the tension.
Anyway, I put this neck problem down partly to my pulsations. It happens sometimes if I've been out walking my dog and bend over to take off his leash. The eye will pulsate for a bit. Every time, it's stopped by itself after a few seconds.
When I first noticed it, I went to the optometrist for my regular eye checkup and asked her about it. She had no answer for me.
I know it also can be caused by high blood pressure (I don't have that), but if you think about it, your blood pressure does go up when you are exercising, tense or even when you are overheated. There seem to be many causes for it, but it would appear that it's nothing to worry about unless it becomes worse or something else happens with your eyes.
I have those irritating floaters too. They used to be a dot here and there, but now I have what i can only describe as blobs of jelly floating across the surface. This gets worse if I'm tired and if I eat a lot of sugar. I need another eye exam now, so my need for new glasses probably contributes to some of it too.
Sylvia
---------- Post added at 15:40 ---------- Previous post was at 15:16 ----------
I have ugly gobs of something floating in my eyes that the doc says are floaters and there's nothing we can do about them. They've gotten so much worse in recent years but he still insists they're very common.
Now and then, I have those light flashes in my eyes. They start with a loss of vision in part of my eye that slowly moves to the centre of my eye so I can't see people's faces on TV. It's not so noticeable if I'm looking into the distance. Eventually, the block will start shimmering and look like the jagged edge of a zipper. This I equate with a flash of lightning.
I've been to a specialist who said nothing was wrong. It went away for a few years and recently returned. I looked it up on the internet (official medical sites) and found out that these are what they call eye migraines. Some people have them with pain only, some with flashes of light and temporary vision blockages with no pain. I have no pain with mine. These tend to last up to 20-30 minutes, which is exactly the description given. This is possibly what you are getting with those flashes.
Here are 2 sites that explain ocular migraines:
allaboutvision.com/conditions/ocular-migraine.htm
webmd.com/migraines-headaches/guide/ocular-migraine-basics
Hope this helps.
Sylvia