Comments on: Illusion-o-rama

By: Al

Al — Tue, 15 Jul 2008 11:17:13 +0000

The blind spot is where the optic nerve goes through the retina. As the nerve connections (also blood vessels) are situated in front of the light-sensitive cells, there is a gap in the coverage to accommodate them.

By: Michael L

Michael L — Tue, 15 Jul 2008 09:20:40 +0000

So, on the flip side of this, what causes the blind spot?

By: CanadianLeigh

CanadianLeigh — Tue, 15 Jul 2008 08:32:18 +0000

Hi Brian, regarding Michael L’s question. I had noticed one exception to averted vision giving better vision at night and that is when I was trying to split doubles. They seem to blur together when you avert your vision. I finally understood why this happens when I read the article by Stephen James O’Meara in August’s issue of Astronomy. The article is titled Vanishing Acts, part 2. As splitting doubles is one of my fun pastimes when out observing, I found the article very interesting and instructive. As explained in greater detail in the article, direct vision will only work better if the stars are both bright enough and not to different in brightness. Before reading this article I just thought my eyes were getting too old.

By: MaDeR

MaDeR — Tue, 15 Jul 2008 06:39:27 +0000

Wow, what for here sticked climate troll?

By: madge

madge — Tue, 15 Jul 2008 05:19:45 +0000

Doh Brian beat me too it

By: Brian

Brian — Tue, 15 Jul 2008 02:19:25 +0000

Michael L: That’s because the color-sensitive cones are mostly jammed into a little circle at the center of your retina. The rest of the retina has a higher population of rods, which can only see in black-and-white but are more sensitive to faint amounts of light.

By: A Real Climatologist

A Real Climatologist — Tue, 15 Jul 2008 00:21:12 +0000

Then you must love the illusion of globull warming. Stick to what you know best; astronomy. You know little about earth science.