Children with disabilities in the 1960s were hidden away from the outside world. Martin, being blind faced rejection as a child, which I believe led him to become blind in many other ways.
By generalising the attitudes of people using experiences of the past, Martin traps himself in the bitter memories of his childhood, causing him to be "blind" towards the present world. For example, as a child he never trusted his mother.
"You"re ashamed of me, you never tell the truth," was his embittered words towards her. Presently, Martin is callous to Celia, whom he sees as a mother-like figure and hence generalises that she too must be untrustworthy and ashamed of him. It is his fixation on his past that is responsible for his inability to see the "real" Celia. .
Martin is also colour blind in the sense that he only sees the world in black or white. He is quick to condemn people as either good or bad, and cannot see people for being anything in between. We can see this in his friendly manner towards Andy whom he categorises as good, and in his brusque manner towards Celia whom he classifies as bad. He cannot see Andy for being anything other than trustworthy and Celia for anything other than dishonest. However Andy cures Martin's blindness when he lies to Martin about a photograph and confesses his affair with Celia. .
He shows Martin that there is an "in between" with the truthful quote, "Everybody lies but not all the time". .
Martin is also blind to love and affection as he hides from all traces of it. For example when Celia tries to seduce him, he backs away, reacting with intense anger. This is most likely to do with his lack of trust in people, however is Martin truly to be blamed for his behaviour, as he does not have the eyes to see the world, and people for who they really are. .
