What do you understand from the term colour blindness?

Have you ever got a chance to interact with a colour blinded person? If yes, you'll probably be able to understand how a colour blind person perceives colours. Such people may see no or few colours. But imagine, they have no idea whether or not how they think a colour looks like is actually right! For instance, if they look at tree and don't see green the way we all do, how would they know what the 'real' green colour looks like? Isn't it unbelievable? Dr Keller Wortham from USA explains what defects in eyes usually cause colour blindness. We perceive colours based on how they reflect light and if light-sensitive cells in our retina fail to take those signal, the result is colour blindness. Dr Wortham also busts some myths around this condition. He explains how the condition is more like a colour deficiency than colour blindness. The reason behind this condition could be genetic. In that case, unfortunately, there is no treatment. However, if it's caused by any other reason or condition, there might be an underlying treatment. There are number of people with this condition. The expectation from the society is to understand it and help such people wade through day-to-day difficulties they might face.