A 70-year-old man who had taken kratom every day for four years went to eye specialists with two unsettling complaints. His vision in dim light was getting worse, and he was seeing something like television static across his field of view.
Retina specialists at Wills Eye Hospital and Thomas Jefferson University in Philadelphia found abnormalities in both eyes, in the retinal layers that detect light and support that process. They also noted darkened skin, and a urine test was positive for mitragynine, kratom's main active compound.
