Judy Marks, age 11, of Norristown, Pennsylvania, for her question:

Is it true that a look at the sun can blind you?

Yes, this certainly is true. Human eyes are not made to look directly at the sun. When a person does this, even for a very short time, fierce little sunbeams dart through the open eyes and damage the retina screen back of the eyeballs. We need these retinas to see and if only a few of their cells are damaged, the eyesight is damaged. For doctors are unable to repair a retina that has been destroyed by the fierce light of the sun.

Some people think that the sun is dangerous to the eyes only when it shines high and bright in the sky. Not so. It is dangerous to stare directly at the sun at any time. So when we admire the comet, let's make quite sure that our precious eyes are shielded from the direct glare of the setting sun.