Standing Darkness?

[Eye_problem_guy]

More and more lately I notice that, after sitting for a period of time (that is becoming increasingly less in necessary duration) that when i stand, my vision clouds with blackness for a period of about 20 seconds, slowly clearing. I have also begun to notice headaches after such, for lack of a better word, episodes. I doubt degeneration, because I am a teenager, but then again I don't know (and i know age context is important). At this point, it is just an inconvenience, but will it get worse, or will the headaches get worse?

Thanks

[John C Hagan III, MD, FACS, FAAO]

Okay, this is a simple explanation of "orthostatic hypotension".  Suppose you're carrying a bucket of water on flat ground for a while. Your heart gets use to a certain amount of work to do this. Suddenly you start carrying the bucket of what up a long flight of steep chairs. You get breathless and it's much much harder to do. Your heart has to speed up to do the extra work. You may even have to stop and rest.


Now suppose you're laying down or sitting down. Your head is either at the same level as your heart or not far from it. If you're sitting down blood often "pools" in your lets. Now you suddenly stand up and start to walk. The heart has to work much harder because the head is not "level" with the heart. In people that have slow heart rates (the young, the fit and some on certain medications) it takes a few seconds to get the message to pump harder. The brain is so sensitive to reduced blood flow that the person is often dizzy, their vision starts to black out and some people even faint.

This can be countered by getting up slowly after being flat (in bed, on a couch) or after being seated for a long time. In hot weather saying hydrated often helps.

I personally have orthostatic hypotensis partly from having a slow heart rate (I'm a distance runner) and partly due to a medication I take.

JCH III MD    Eye Physician and Surgeon

[Just_Sort_Of_Confused]

Oh my, I seem to have the same problem as you do.

Exactly, when I stand up from sitting, my vision goes black, and I get this really dizzy feeling. It lasts for about ten to twenty seconds, then slowly clears. I don't know what it is, but I am very concerned on whether I will lose my vision at a very young age.

[John C Hagan III, MD, FACS, FAAO]

Please review recent posts on the two Eye Care Forums that present idential complaints.

Far and away the most common thing that causes this is called "orthostatic hypotension". Use a internet search engine and look this term up to learn about what causes it.

There are other causes, some serious, but they are much less likely.

Even given what I just said, you need to see an ophthalmologist (Eye MD) for a baseline comprehensive medical eye examination and your personal physician for a general physical examination. Be sure to tell both physicians about your visual blackening with changes in position.

JCH III MD  Eye PHysician and Surgeon