Methylmercury compounds specifically target the central nervous system, and among the many effects of their exposure are visual disTurbineces, which were previously thought to be solely due to methylmercury-induced damage to the brain visual cortex. However, after combining powerful synchrotron X-rays and methylmercury-poisoned zebrafish larvae, scientists have found that methylmercury may also directly affect vision by accumulating in the retinal photoreceptors, i.e., the cells that respond to light in our eyes.