Why see white when eyes closed and startled?

[marmaduke]

Why do you see white when your eyes are close and something startles you?

[rojash]

I don't

[Kilala]

I can't say I have noticed it, but I do have a theory...

When you are startled, your blood rushes to the bits of you it needs to protect most, and your legs, so all that extra oxygen will allow you to run away quicker.  Therefore you can suddenly feel cold, your legs can twitch quite violently, your heart will race, you will go pale and you can feel sick as the blood leaves your digestive system quickly.  Then after a break, you may well become flushed and hot.  The blood inside your eyelids may well be withdrawn to more vital areas.  That combined with your pupils dilating to best see the assailant means you can see the light through your eyelids.

Unless you are in the dark.. then you are on your own there, mate!