Pulsation in eye

I am having an issue with one of my eyes where it feels like is continually pulsating, it’s been doing this for a week now. It is not a twitch as I have had those before and a twitch you can visually see. I’ve been to two eye specialists and they are not sure what the cause is. I am not having pain or vision problems, just the pulsation. I’ve been under a lot of stress so that might be the cause, but am wondering if anyone else has had a similar issue and what was the diagnosis.
Thanks