When looking up at the stars on a clear night why is it that...?

The real faint stars can only be seen when I look slightly to the left or right of it but not when I look directly at it?When looking up at the stars on a clear night why is it that...?
This is a well known phenomenon among amateur astronomers, who frequently look away from something (a little) to see it better. That's called averted vision, and it works because the rods in your eye (which sense black and white night vision, not color for day vision) are more sparsely distributed around the region where the prime focus of your eye lens concentrates the image directly. That in turn is because that is where the optic nerve enters the eye. So it is true that if you want to see something that's really faint, it sometimes helps to focus slightly off - center from the actual target.When looking up at the stars on a clear night why is it that...?
This is called averted vision-- we use this to see very faint objects with our telescopes-- by looking slightly left or right of the object-- but NOT directly at it.... as indicated in the above answers.
we all have a 'blind spot' at the center of the retina, just because it's where all the blood vessels converge and there's no color receptors there........see the photo here... a littlepast halfway... bright colors...





http://photography.qj.net/Educational/ci鈥?/a>





http://img.qj.net/uploads/articles_modul鈥?/a>





so things that are that little, looking at it dead center, they'll not be visible unless you look aside a little bit....
It so happens that the part of your eye's retina which is most sensitive to dim light, is not in the exact middle of the retina, but slightly off to the side. That means, when you look slightly to the side, the dim light is striking that more sensitive spot, so you're able to sense the light better.





This is an effect well known to amateur astronomers; they call it ';averted vision.'; When you're looking at something dim like a nebula through a telescope, you can often get a better view of it by slightly averting your eyes from it.