light is responsible for life on Earth because Without light there would be no life. Plants need light to produce food through the process known as photosynthesis. Light is the only way for plants to get the energy to grow. Animals depend on plants for their foods, rather directly or indirectly. Human beings too eat plants, or animals that eat plants. Without light, all the plants on earth would die and animals and people would be left without food and would die too.
Light is also important because it gives the earth the warmth needed to support different forms of life.
Some living creatures like fireflies create their own light. Others like man have learnt to create artificial light when natural light is not available.
Light lets us see things. Without any light we would see nothing at all.