An ancient religious story tells of a man who was travelling along the road to Damascus. Suddenly, his pathway was suffused by light. The light blinded the man, yet also opened his spiritual eyes to the ways of God. Light has this dual potential. It can both enlighten and strike blindness. It can bring health and take it from us.
Our eyes most readily respond to light, and they are well adapted to react swiftly to variations of light and dark. But it is our skin that needs more attention. Exposure to light will allow the body to generate vitamin D, which is thought to help protect us from a range of conditions. But when that light becomes too concentrated, it will burn skin and set the conditions for cancers.
Our pattern of life provides little opportunity to moderate exposure to light. Hidden indoors in our various modes of activity, we lose the regular daily dose; then overdose when we get a chance for leisure.
Those of us higher in the hemispheres cope with substantial seasonal variation. The paler the skin, the more capacity it has to absorb light. This allows maximum benefit from minimum light, but at the same time poses a higher risk of overdose. Those with darker skins close to the equator have greater exposure but greater protection.
Perhaps a spiritual approach to light might aid us in moderating our physical exposure. Maybe, like the pilgrim on his way to Damascus, we should seek spiritual enlightenment outside. And take care that the radiance of the universe does not dazzle or burn.