Andrew Huberman· PhD
And what I mean by that is that every cell of your body, meaning a cell that is part of your bone tissue or your bone marrow or heart tissue or liver or spleen, if light can access those cells, it will change the way that those cells function for better or for worse. For many organs within our body that reside deep to our skin, light never arrives at those cells. A really good example of this that we'll touch on later is the spleen. Unless you have massive damage to your body surface, unless you literally have a hole in your body, light will never land directly on your spleen, but the spleen still responds to light information through indirect pathways. And those indirect pathways arise through light arriving on the skin and light arriving on the eyes.