During the time of Sakyamuni Buddha, a man was born blind. This blind man had a good friend who was trying to explain to him about the existence of light. However, the blind man responded, "I do not believe in the world of light. There is no such thing as light. If it existed, I should be able to touch it. It has no substance and thus it is not real. Everything real has weight but I feel no weight or shape where you see light. If light really existed, it would emit sound as soon as I strike it. It would also have a particular taste or aroma. Since this light has no weight, shape, sound, taste or smell, therefore it does not exist."

His friend then decided to seek the advice from Buddha and then Buddha said, "There is no use trying to argue with him about the existence of light but take him to see a physician, maybe the physician can offer some help."

Then he took his blind friend to visit a physician and upon checking, the physician managed to detect the cause of his blindness which was due to the cataract. After the physician applied remedies to the cataract, his vision was restored. At the moment when he saw light for the very first time, there were tears in his eyes. He immediately said, "So, this is light!"

The existence of light cannot be explained theoretically to the blind man. The blind person cannot appreciate its existence but could immediately realize its existence once he could see it. The cataract represents the illusion of thought and many of us are like the blind man when it comes to the mystical essence of truth. It cannot be explained theoretically about its existence and validity. A lot of us are still ignorant of the truth and reality about our existence in the universe. This is because our vision, which is our perception of the world act in the same way like the blind man