bulb

The main differences between medical devices and High Street masks are the strength of the LEDs, the number of bulbs on the device and how close they sit to the skin's surface when being used.

They had to constantly clean the house and change every light bulb in the home to bright white for filming purposes, she said.

"Now we've got a little pen torch, just in case, whereas the old pitmen's lamps used to have a little bulb, but if your battery fused you were up the creek really."

Spraying insulin up the nose — where brain tissue reaches outside the brain, making up the olfactory bulb — improves cognition in people with early Alzheimer’s dementia and with mild cognitive impairment.

"A human being's like a light bulb. And we enjoy that light inside, but we also radiate it. We affect our environment. Everybody knows that," he says in the clip.