Among the different types of cancer treatment, photodynamic therapy -- where light in is used to destroy malignant cells -- has one of the strangest side effects, Science Alert reports: patients are often better able to see in the dark.
Now researchers have figured out why: a light-sensitive protein called rhodopsin interacts with a photosensitive compound called chlorin e6, a component of this type of cancer treatment.
It's all about an organic compound called retinal, which is found in the eye and usually isn't sensitive to infrared light.
Visible light triggers retinal to separate from rhodopsin, and this is converted into the electrical signal our brains interpret to see. We don't get much visible light at night, but it turns out this mechanism can also be triggered with another combination of light and chemistry.
Under infrared light and with a chlorin injection, retinal changes in the same way as it does under visible light.
"This explains the increase in night-time visual acuity," according to chemist Antonio Monari of the University of Lorraine in France.
Read the full story: