There is mounting evidence that the blue-light-spectrum-heavy light emitted by LEDs (including LED monitors and TVs) can promote retinal damage. The chemical reactions within the light receptors require a balanced spectrum to convert back to molecules that are receptive to incoming photons. If they don't receive this balanced (red natural) light spectrum, the resulting free radicals damage retinal tissues, eventually leading to macular degeneration and even blindness.
I predict we will have a generation of people with premature macular degeneration as a result of excessive LED lighting.
Look for natural spectrum lighting from incandescent, halogen, natural outdoor sunlight. But not too bright! Aim for a happy medium. Steer clear of LEDs and fluorescents.