The fear of heights experienced by acrophobics is no small matter; tall buildings, airplane rides, bridges, even stepladders may present a paralyzing challenge. A new therapeutic approach, however, can help to lessen the anxiety experienced by acrophobics.

Ralph Lamsen, of the Kaiser Permanente Medical Group, uses virtual reality to desensitize acrophobes to their fear. The virtual world experienced through the helmet, glove, and handgrip presents a series of challenges relevant to the phobic situation. For example, clients are presented with a plank they must cross, an experience that usually produces elevated heart rate and blood pressure. Clients are encouraged to progress at a comfortable pace, staying at the edge of the plank until read ...

Do animals see the same way we do? Do some animals have better vision than humans? The senses of animals have evolved to give members of the species an optimum chance for survival. Here are a few examples:

Some animals, such as cats, have a reflective surface ( tapetum) on the back of the eye behind the sensory receptors (left image above). When light first enters the eye, some light is detected by the sensory receptors. The light not detected by the sensory receptors continues onto the reflective surface at the back of the eye. This light is then reflected outward toward the sensory receptors, providing a second opportunity for detection. This feature produces two results. First, the outward reflection results in the shining of the cat's ey ...