Although roaches do have excellent eyesight, they have some limitations. For instance, their lenses grow progressively more misshapen toward the outer edge of the eye. Lens irregularities can also affect vision in the middle of the eye, though that is less common, and since they have so many, usually not a big deal. Cockroaches also cannot see in red light, though they do see quite well in green light. As important as the eyes are, however, it is important to note that cockroaches, unlike most other animals, can live for some time without their heads.