I'm not sure what kind of light you are talking about. As in natural light from the sun of electric light from a flash light but both are extremely important for an apocalypse. I'm going to assume you are talking about natural light. Without the light of the sun it will not only be difficult to see but will be horrible for your health without any light to provide vitamin D and warm your body. Another thing, with light is that some types of light provides heat and heat is very important if you are trying to survive. Now lets talk about artificial light. Artificial light comes in handy with being able to see in dark places and gives you an upper hand in surviving an apocalypse where almost half of the world will not have access to electricity.
