Odd effects caused by bad vision?

Question

I wear disposable contacts and my prescription is -7.45 in both eyes. I can barely see a foot infront of me when I have them out. But last night, when I took out my contacts to go to bed, I was starring at the small green light from the air conditioner in the room. Since it was about 5 to 6 feet away from me it looked very blurry. What I say next might sound odd but after starring at the light for a few minutes it was like I was looking at the surface of my eye but it was in focus and I saw small black dots that moved slightly only when I blinked. Has anyone else with bad vision ever experienced any odd visuals when not wearing contacts/glasses?

Answer 1

You are actually getting a projection of dust particles in your tears onto your retina.  It works where a small bright source is expanded into a distinct disc.

A similar effect can can be produced with a technique using a +12 D lens to let people without a major refractive error see their own developing cataracts in some cases.

( I didn't do it to everyone, but some people found it very informative, and better than ten minutes of attempted explanation.)

If it had been a red light, you might hav also seen cigar shaped blue flashes extending out from the red spot.

There are a whole range of odd things that the internal structure of the eye can throw up as visual effects.

The formal name is "entoptic phenomena."

Answer 2

you dont need bad vision to see that. sometimes you can even see it in a dark room with your eyes closed. its just they way your eyes react to darkness