Meredith R. Klifto, MD, is an assistant professor of ophthalmology at the University of North Carolina School of Medicine, Chapel Hill. As a board-certified ophthalmologist, she specializes in ...

Sound waves don’t scale with you. At a tiny size, most human-made sounds (even someone talking nearby) would be too low-frequency to register. Your eardrums simply wouldn’t be large enough to pick up ...

Optimal” levels on a blood test are the optimal levels that show the most benefit, which help reduce fatigue and age-related ...