Answer:
Braille is a system of raised dots that can be read with the fingers by people who are blind and they can recognize the dots by their fingers which have touch receptors.
Step-by-step explanation:
Sensory receptors perform various functions in our bodies. During vision, photo receptors respond to light intensity and color, but those people who are blind do not have functional photo receptors that is why they use their touch sense to recognize letters and words for reading. The technique is called braille system. Braille symbols are formed within units of space known as braille cells. A full braille cell consists of six raised dots arranged in two parallel rows each having three dots. These dots are touched by fingers and touch sensors in fingers take signals to the brain which takes no time to respond and hence the letters are recognized by the reader.