I am sure many of us have faced it. Getting up quickly from the sofa or out of bed, and suddenly the world dims, blurs or goes dark around the edges. You might feel a little dizzy too. A few seconds later, everything is back to normal, and you carry on as if nothing happened.
Almost all of us have had this experience, and it is usually nothing to worry about. We spoke to two eye doctors about what is going on, why it happens more on some days than others, the easy fixes, and the signs that mean it is time to get checked.
What happens when you stand up too fast
Dr. S Dhivya Pratheepa, consultant ophthalmologist at Dr Agarwals Eye Hospital, Chennai, describes one of the most common reasons . “When you suddenly stand up from sitting or lying down your blood pressure may temporarily drop,” she says, adding that the brain receives less blood flow causing your vision to go dark and this is called orthostatic hypotension. “But after some time once the circulation adjusts your vision comes back to normal,” she says.
Normally, “the blood and the heart rate adjust so quickly that the blood vessel tone also changes, so it maintains the blood flow to the brain and the eyes,” says Dr. S. Laavanyaa, who is also a consultant ophthalmologist at SRM Prime Hospital, Chennai. “If due to some cause, this adjustment is delayed, then there will be a brief dimming of vision, dizziness, or a feeling that we might faint,” she adds.
Why it happens more on some days
One could face it more on some days than usual. “This happens when you are dehydrated, you have had poor sleep or you are physically exhausted due to heavy exercise and failed to replenish yourself with fluids,” Dr. Pratheepa says.
Dr. Laavanyaa adds a few more triggers. “Besides dehydration, other common reasons for this could be the use of certain medications, anaemia, prolonged bed rest, and some underlying medical conditions,” she says.
Simple fixes that help
If it happens occasionally or lasts only for a few seconds, following which it resolves completely, Dr. Laavanyaa says that it might not indicate any serious eye problem. “However, if the episodes are recurrent, it should never be ignored,” she cautions, adding that it is always better to check the blood pressure, and your doctor might check it while lying down and while standing.
“When there is generally nothing to worry, you can get up slowly especially after lying down for a long time, stay adequately hydrated and sit or lie down immediately if you feel faint,” she advises.
Warning signs worth getting checked
If it is associated with temporary loss of vision in only one eye or associated with black spots or flashes, according to Dr. Pratheepa, one should get a complete ophthalmological checkup for both eyes.
“There is also an important warning, not every episode of temporary visual loss is caused by low BP,” says Dr. Laavanyaa. “Sudden loss of vision in one eye, persistent dark curtain or shadow, repeated episodes, it is accompanied by difficulty in speaking, weakness, severe headache, you need to consult a doctor immediately especially if it is going to be in one eye,” she explains.
“I would like to say listen to what your body is telling you because your vision is precious,” Dr. Laavanyaa concludes.
In a nutshell, a moment of darkness when you stand up is usually your body catching up with gravity, and it passes within seconds. Getting up slowly, drinking enough water and getting proper sleep can make it far less likely to happen. But if it keeps coming back, affects only one eye, or comes with flashes, black spots, weakness or trouble speaking, don’t ignore it. Get it checked.
