There are thousands of chemicals, mostly dyes, used to create tattoos. Some of them are known carcinogens. Although the tattoo-cancer link is weak, people who are worried can get them removed. But the lasers that remove tattoos react with some inks and produce a different set of carcinogens—a strange but interesting problem.
Scientists from Mexico have discovered a very clever way of getting rid of HPV, the most common of all sexually transmitted infections. It's done using a simple chemical and a laser -- and there's no harm to normal cells. This method could represent a big advance in eradicating the virus and reducing HPV-related cancers, especially cervical cancer.
Tears of the retina are fairly common and they can lead to blindness. Fortunately, there's a quick and nearly-painless repair method that requires a few zaps of a laser. Dr. Chen, an ophthalmological surgeon at Columbia University, explains how a miraculous beam of light can produce incredible changes deep within the eye.