I’m taking about the bright dots which appear that seem to zip around in your sight for five seconds or so, usually after one of the above…..?
In: Biology
AFAIK, what you see are the white cells which are huge compared to others reflecting light and hitting the retina from the back
Not sure about taking a blow to the head but feeling faint/seeing stars when you stand up too fast is due to the sudden drop in blood pressure.
The medical term is o**rthostatic hypotension (thx for pointing out typo)** or **postural hypotension**
I assume blood pressure tend to drop after a big stretch or after taking a blow to head as well which may well explain that phenomenon
In my personal experience following a blow to the head it was a case of retina issues. Turns out my retinas were detaching and I required laser eye surgery.
But the blow I received to my head was monumental
If you see Stars after you stretch, that’s a sign that death is closer than your mom wants it to be.
What if this happens frequently when you stand up from laying down and have fallen over many times. (Never been injures. Usually “controlled falls” as I know what’s happening. But still have to go down for a second or two to equalize)
The “stars” (or rather static) you see is your brain losing connection to the simulation you live in. Once you re-establish a full connection to the simulated universe, you go back to seeing the stuff being generated clearly.
“When we get out of bed or stand up, the blood vessels in our body need to clamp down rapidly to maintain blood pressure going to the brain. If we stand too quickly, blood pressure can drop and cause dizziness, lightheadedness or fuzzy vision. This may just be a symptom of getting up too quickly, so it’s important when getting out of bed in the morning to do so slowly.”
Basically, your body gets shocked by you moving so fast and is working hard to get blood to your brain. This causes a dip in blood pressure. Not entirely sure how blood pressure relates to vision though, had a hard time finding anything that explained it.
Unfortunately I have no explanation, but I just want to attest that I know exactly what you mean (by the comments so far, not everyone seems to)!
It’s like a bunch of white fireworks stars making quick sprints in multiple directions in your field of vision, then disappearing after a couple seconds, right? Meanwhile your vision is not blurred or dimmed at all, just these bright dots appear in the foreground for a while and then are gone.
Also not the same thing as feeling dizzy from low blood pressure, because that includes feeling weak and fainty, and the visual symptoms are more, umm, stationary.
I get this only immediately after lifting something heavy or gratuitous physical exertion. There’s a lot of people saying its because its from a sudden drop in blood pressure but that doesn’t directly answer the ‘why the stars’ part.
Here is a more complete answer!
Both of [these situations] are basically artificial phenomena in a sense that in one case – the standing up too quickly – this is an entoptic phenomenon, which means “something going on inside the eyeball”. The retina, as you’ll know as an ophthalmologist, has one of the highest metabolic rates of any tissue in the body. The brain and central nervous system tissue burn off about 20% of the energy that you consume in any given moment in time and yet they contribute only a small fraction [about 2%] of body mass. So the retina is very metabolically hungry. And if you stand up too quickly you can have what’s called a “postural drop” in blood pressure. When you stand up, and before your heart compensates, the return of blood drops slightly which causes the perfusion pressure to drop briefly. That causes a momentary reduction in perfusion of your retina. That slightly reduces the supply of oxygen and sugar to the retina from the blood, which causes the retina to start to fire off abnormal signals, which we experience as “sparkly” light signals; the brain is fooled into thinking you’re seeing light when it’s not there.
Familiar from cartoon strips, this bizarre phenomenon is caused by the generation of so-called phosphenes – illusory flashes of light caused by pressure on the light-receiving cells in our eyes. The simplest – and least painful – way of generating them is by gently pressing on your closed eyelids then opening your eyes. Isaac Newton came up with another method while investigating the nature of light: sliding a bodkin (a think, blunt needle) between his eye and the socket-bone. Not recommended. From science focus. com
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