© Thomas Peter / Reuters
The study, carried out by optical chemistry researchers at the University of Toledo, explains how exposure to blue light can cause age-related macular degeneration - one of the leading worldwide causes of blindness.
"It's no secret that blue light harms our vision by damaging the eye's retina. Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration, such as a new kind of eye drop," study co-author Ajith Karunarathne said.
Macular degeneration occurs when photoreceptor cells in the retina die - these cells need molecules called retinal in order to sense light and trigger signals to the brain.
During lab experiments, the team found that blue light exposure causes retinal to trigger reactions that generate poisonous chemical molecules in photoreceptor cells.
"It's toxic. If you shine blue light on retinal, the retinal kills photoreceptor cells as the signaling molecule on the membrane dissolves," study co-author Kasun Ratnayake said.
The cells do not regenerate, so "when they're dead, they're dead for good," Ratnayake added.
The team introduced retinal molecules to other cell types in the body, such as cancer cells, heart cells and neurons to establish if it could kill other cell types.
"The retinal-generated toxicity by blue light is universal. It can kill any cell type," Karunarathne said. Blue light alone or retinal without blue light had no effect on cells, however.
The lab currently is measuring light coming from television, cell phone and tablet screens to get a better grasp of how the cells in the eyes respond to everyday blue light exposure.
Details of the research have been published in Scientific Reports.
Reader Comments
The point the article makes seems to be correct to me.
Most people would rather divert the conversation in a flash, by any means necessary, when the phrase "Ditch your phone" gets a mench.
Clearly, anti-smoking propaganda is highly addictive.
Yup, and I think I stumbled upon a reason why:
According to Dr. Robert Lustig: "What is the difference between marketing and propaganda? Marketing is using information to espouse your point of view. Propaganda is using disinformation to espouse your point of view. The difference is the truth. If you’re telling the truth, it’s marketing. If you’re telling a lie, it’s propaganda. Point is, propaganda does things to our brain because what it does is it gives us a dopamine boost. It makes you zealous. It increases your zealotry, whether it be for any specific political point of view, or any specific religious point of view or any specific material consumption point of view. Ultimately, those are all found in dopamine.
(P)ropaganda is a great way to drive your dopamine. Conversely, serotonin is the contentment neurotransmitter. Here’s the problem, dopamine is an excitatory neurotransmitter, so neurons want to be excited because after all that’s why they have receptors in the first place, but neurons are fragile. They like to be tickled, not bludgeoned. Dopamine over-stimulation causes neuron cell death. Now, you don’t want that. So neurons have a plan B. They have a self-defense mechanism. What they do is they down- regulate the number of receptors. So in human terms what this means is you get a hit, you get a rush, receptors go down, next time you need a bigger hit to get the same rush and then a bigger hit, and a bigger hit, and a bigger hit until finally you get a huge hit to get nothing. That’s called tolerance. And then when the neurons actually start to die, that’s called addiction.
But serotonin is an inhibitory neurotransmitter. It doesn’t down-regulate its own receptor. It doesn’t need to. So you can’t overdose on too much happiness, but there’s one thing that down-regulates serotonin, dopamine. So the more pleasure you seek, the more unhappy you get. And when we are propagandized by industries for their purposes to activate our dopamine, we fall into the perpetualness of addiction and depression."
[Link]