Lab rats have been subjected to gene therapy that triggers erections on demand when the animals are exposed to blue light.
The breakthrough could pave the way for a treatment for human erectile dysfunction, which affects more than half of all men over 60.
While some men reach for a little blue pill - Viagra - in order to deal with the problem, researchers from ETH Zürich believe that in the future they may simply need to switch on a blue light in order to stand to attention.
The team - led by Professor Martin Fussenegger - injected the erectile tissue of rats penises with a gene construct that reacts to blue light. The blue light was used to trigger erections on demand
After treatment, a blue light shone on the underside of the animal would cause its penis to become erect.
It works by triggering a reaction that reduces calcium levels in the cells, which then relaxes muscle cells and increases blood flow to the erectile tissue.
Speaking for all older men, "Yeah, we'll try that". I can just see it now. "OK, baby, flip the switch for the blue light and watch what happens. Whoopee!"