For years, cancer patients have reported seeing flashes of light during radiation therapy. After careful observation, scientists have caught this light on camera, and discovered what causes it.
Cherenkov radiation is a type of light caused by charged particles (such as electrons) travelling through a material at high speed. This effect is the reason that underwater nuclear reactors glow blue.
Scientists discovered that when the radiation used in cancer treatment passes through a patient’s eye, it causes a small flash of Cherenkov radiation. Patients can see this light even if their eyes are closed, because it’s happening inside them.
These flashes aren’t harmful – in fact, there is evidence that suggests seeing them is actually a better sign for long-term vision. Now that scientists are able to measure the light for themselves, research into these effects will be much more reliable and able to help more patients with their recovery.
This article was published in Issue 40 of Double Helix magazine (https://www.csiro.au/en/Education/Double-Helix). Copyright for this article is held by CSIRO.
Lachlan Writes Science 