Possibly you've blacked out for a brief moment, lost your vision momentarily, and you wonder why it even happened. Generally, it is not cause for concern and could have a relatively simple explanation. Of course, if you are particularly concerned, or you come close to passing out, or do faint, you will want to consult a physician. It is always wise to consult a doctor in regards to these medical issues.
Here we will explore the various possibilities for why you might blackout for a second.
Low Blood Pressure
Some people will experience a brief blackout when they stand up. This is caused by low blood pressure, blood unable to go to the head and so it falls towards the lower body. This is called orthostatic hypotension or postural hypotension. Of course, within a moment, when blood pressure returns to normal, you regain vision and blood flows to the head.
It is important to know that vision is a process that occurs between the brain and the structure of the eyes, and blood flow is necessary for this operation to occur.
It is possible that there is a tear at the retina that can cause vision loss for brief moments, because, of course, the eye might not be functioning fully if this has occurred. If a tear happens in the retina, fluid gets behind the retina and lifts it off the wall of the eye, causing a perceived darkness of vision.
Some vascular problems can interfere with the structural pathways in the eye that affect vision. Diabetes, retinal artery or vein occlusion, hemorrhage and vasospasm can affect vision. There needs to be, as stated before, sufficient blood, for oxygen, going between brain and eyes for vision to function properly. Vascular problems can hinder this flow.
A mini-stroke can also affect vision.
Other Possible Causes
Other causes of a vision blackout include:
- High blood pressure
- Visual migraine (painful headache)
- Optic neuropathy
- Giant cell arteritis
- Increased intracranial pressure (in the skull)
- Ocular ischemia (not enough blood flow in eye from carotid artery)
So, if your vision darkens, you might be having low blood pressure issues, other vascular problems, a retinal detachment or other issues with the structure of the eyes. It is important to see a doctor if you start to feel like you might faint or if you have other issues that might indicate something as serious as a stroke, like paralysis, confusion or speech impairment.
Possible Causes of Visual Blackout
|Low Blood Pressure||Vascular Problems||Retinal Detachment|
Blood is not flowing adequately to brain and eyes
High blood pressure, strokes and other vascular problems can interfere with blood flow to eyes and hinder vision
If the retina tears, fluid can build between retina and wall of eye and hinder vision