Light headed

[andy_wood]

Today i cut my thumb and it bleeded violently. I understand all the blood was going to my thumb but during this i couldnt properly see. Why did this cause me to have blurred vision

[fantastical]

I once lifted something so heavy, that I literally was "seeing stars," tiny bursts of light radiating from the pupil of my eye.

I don't know why your bled thumb caused you vision to blur, nor do I know why my sight was effected from muscular strain. My best guess is that your brain, and bloodflow to it, was too busy tending to your inoperable thumb. Bloodflow was not reaching the brain as normal, therefore the first organ that feels this effect is the eye (ie your sight).

Did you know? The eye is the human's only physical extension of the brain. The eyes are what protrude from the development of the brain while a fetus in the womb.

[bobbyx]

Once, I went to the gym too soon after dinner and over exerted myself, I felt faint then went blind for what seemed like five minutes (it was probably less though).

 

It the body's way of coping, much like when Scotty shuts down non-vital systems to keep the Enterprise running!

[fantastical]

But your eyesight is not "non-vital," is it? I'd say quite the contrary. I see your metaphor, though.

[Hamish]

Sometimes shock can cause your blood pressure to drop and this will cause dissiness and feinting. I usually happens to me at the dentist, although I'm not too squeenish!

[bobbyx]

chaotic1:

 

I reckon a temporary ocular shut-down would be preferable to a cardiovascular one, don't you?

[AB Editor]

For all medical questions, we strongly advise you to seek professional advice from your doctor or a healthcare professional.  Please do not rely on, or wait for, advice from Answerbank users.

[fantastical]

I concur bobbyx!

[KEJ2000]

I agree, you may have been temporarily about to faint, but then the feeling of faintness passed (luckily for you) and your vision returned.  I once fainted after seeing myself bleed, I felt nauseous and very dizzy, then my visual field quickly went entirely black (even though my eyes were still wide open!), and that was the last I remember before "coming to" upon the floor.