NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,992 terms related to cancer and medicine.
- listen (lenz)
A clear disk that focuses light, as in a camera or microscope. In the eye, the lens is a clear, curved structure at the front of the eye behind the pupil. It focuses light rays that enter the eye through the pupil, making an image on the retina (light-sensitive layers of nerve tissue at the back of the eye).