The operations were extraordinary. They were no more painful than any minor operation. There was some pain when the anaesthetic wore off, and each eye felt quite sore for some days, but there was no pain that an aspirin could not ameliorate. There was nothing to see during the operations except random sensations, but for me this was when the operation became really interesting.

For many years now I have been explaining that the way our brain operates means that we cannot see reality directly but only the interpretations and meanings that our brain creates out of our past experience. The consequence of this is that we each live in our own world of meaning. The first operation was on my left eye, so I knew that all I could experience was random, unstructured sensations as the lens in the eye was removed and replaced with a plastic one. Meanwhile, all the my right eye could see was a shifting pattern of diffuse blue light and white light created by the blue sheet covering my face and the lights over the operating table. Yet that was not what I perceived. My brain was busy turning these random sensations into meaningful images that I could describe in words. The sensation on my left became a set of horizontal concentric circles like the circles made by Saturn's moons that Professor Brian Cox had talked about in his recent television series. On my right the blue and the white splodges were transformed into a bright blue sky with small fluffy clouds, such as can often be seen in summer in Australia, except that my picture of sky and clouds was set in a rectangular rococo frame.

The second operation taught me something I thought I already knew very well.

If there is one thing that psychologists have proved many times over in many different settings is that we learn far more quickly when we are rewarded for right or nearly right responses than when we are punished for wrong responses. (What we learn from punishment is fear, often followed by rage and the desire for revenge). Psychologists call such rewards 'positive reinforcement'. Young mothers used to be taught that rewarding children spoilt them, and that naughtiness should be dealt with by a hard slap or two. Today young mothers are taught to reward their small children with an almost continuous stream of 'good girl', 'good boy', 'you did that very nicely' and so on. Often now they praise their child for doing what the child had already begun to do, having apparently decided to do just this. Perhaps the child is sitting quietly and the mother notices and praises him for sitting quietly. Most mothers master the technique of positive reinforcement very quickly because they soon see how well it works. In other settings the success of positive reinforcement are not so readily apparent, so many people, especially in certain professions, not to use it. All my experiences of having an operation were where the surgeon treated the patient as an insensate log over which he and his team conducted their conversations. There is nothing lonelier than being the log in such an operation. Now I discovered that this was not what my consultant did. He and his team explained to me what they were doing just before they did it. Moreover, as the operation proceeded, my consultant praised his team for each well-practised movement that was carried out. He included me in this praise.

At about the middle of the second operation, when I judged that my old lens had been removed and the new one was about to be put in, my consultant praised me for lying still. To move at that point in the operation would be the height of stupidity, yet at that moment I did not interpret this praise in this way. Rather I felt a warmth arise from the centre of my being and I was immensely comforted. Thus, I guess, there are times when a small child pays no heed to his mother's rewarding words, and other times when when her praise pierces the shell of the world of meaning in which he lives and assures him that, while he enjoys the privacy of his own world, it is possible to contact others and be contacted by them, and be comforted and strengthened by the touch of a hand or a few simple words.

These past four weeks have not been easy but, apart from the rat, well worthwhile. In a follow-up meeting with my consultant my eyes were tested and I was told that I had 20/20 vision but need reading glasses for small print. I can certainly see the world more clearly now.