Why when i stand up after sitting does my vision become fuzzy, go black and a few seconds later rerurn? i have low blood pressure and don't eat meat

Hypotension : You have postural hypotension, in which your sudden standing up doesn't allow enough time for your heart to pump hard or fast enough to get blood to your head. This is what make you feel dizzy, blurry or even tunnel vision during these episodes. It's best to standup more slowly & wait till you feel ok before moving. You should have your MD check your BP/heart & blood counts to make sure you're ok