Vision

Background

Our eyes provide us with a sense of sight. Unlike many other animals, our eyesight is well developed. We can, not only make out subtle differences in light and shade but also distinguish a wide range of colours. We can see objects close by and also at a great distance. But again, unlike many other animals, we do not put up a good show in poor light. We cannot see anything in the dark. 

Aim

Recognise that light is essential for vision.

Activities

Begin this activity at about 4.00 P.M. Choose a green plant near your house or in a nearby field. Observe the colour of its leaves and record it. Observe the same plant at intervals of 30 minutes until it is very dark. What changes do you observe?

Look around your room at night with the lights switched on. Now switch off the light. What do you see? How do they look? Look at the same room lit by a candle? How does it compare with the previous cases?

Related Questions

Some animals move about at night. How can they see?

What are the colours that can be seen very clearly? Under what conditions? Against what backgrounds?