Day 10 of the bubble, and a fine spring day it is too. It's the sort of day you forget exists after a long winter and makes you realise that 'the sun don't shine any more' is a statement with limited validity.

There is now a significant band of clear vision above the bubble. About 25%. That would make sense if the full absorption of the gas is to complete in six weeks. However, this 25% is about as un-useful as it could be. For a start it is always in the vicinity of the sky when outside or ceilings when inside. I discover that these are the least valuable sources of intelligence when your primary interest is in not tripping over things. But the main thing is that the image is still blurred if you try to look through it. It is still only clear in peripheral vision, where peripheral in this case is 'up' rather than on the left or the right. So, it is an annoying combination of alluring and non-functional — a description that applies to many … well, let's not get into that.

The bubble itself, now occupying the lower 75% of the vision in the right eye, has its own issues. It seems to wobble even more, so shaking my head is like being in a small boat on a rough sea, and the subtle changes in its focal length mean that it often looks as if there is some object or a black dot at about 12 minutes past the hour (north-east-east if you prefer). This sometimes turns out to be just the way the light refracts, but when I study the current dot closely it turns out to be a shape formed of a triangle of low light between the sleeve of my jumper and the desk. Earlier a similar dot resolved as a ghost image of my coffee cup. I have thrown away more than one cup of tea thinking there was a fly or some other large object in it, when in fact it was probably just a black shape created by a vortex as I stirred it This is all very well and liveable with but a touch annoying when you are trying to drink tea.

This brings me to another subject that you might label 'assistive technology'. For years now I have used the speech to text facility on my iphone to write emails and texts, make notes, ask questions in Google and so on. In fact, it is almost possible to fully operate many applications without having to touch the virtual keyboard. This has the usual issues that can also happen with predictive text. The results can be puzzling, amusing or downright embarrassing, like for instance when on inspection of a sent message to my good friend I noted with alarm that it read 'I have a hard on for your daughter' when what I actually had was a far less sexually provocative carton for her. I wonder whether she would still be a friend now had I not noticed this. Years could have gone by with me not understanding why she never got in contact these days. Such are the random effects of tiny perturbations in the electronic world having enormous impacts on life. It did get me to wondering what data these speech-to-text systems get trained on. It would seem to be a dataset in which teenagers are communicating very little except sex talk. I don't have a problem with that except where have all the history, philosophy and science students gone? Or the railway enthusiasts come to that?

I'm wondering whether these detailed observations about my eye are normal. (If you think that my observations over a month are too detailed then let me refer you to a novel by Nicholson Baker called the Mezzanine where most of the plot involves an office worker returning from buying shoelaces during his lunch break). Well, I'm not exactly wondering about whether this writing is normal. I can get onto the definition of what is and what is not normal another time. What I'm angling for is the distinction between what goes on in your head (the brain I mean, not the eye) and what is going on in the outside world. Let's say, for example, that some people live life in their heads while other people live life in the world. This is primarily a matter of what they attend to. Some people are wrapped up in their thoughts, while others are generally observing what is going on in the world. The 'content' of thought can either be to do with thinking about what you are thinking, or it can be about what you are sensing. One way or another you are trying to either make sense of what you are thinking or what you are seeing (or otherwise perceiving).

Psychologists do not seem to have made much of this distinction. There is a purported psychological dimension called 'field dependence' and a test to go with it. This measures the extent to which you are influenced by your perceptions. It can involve making judgements about what is horizontal when sitting in a chair that is at different angles, but the most well-known test is called the embedded figure test, where you must identify shapes embedded within more complex shapes.

But field dependence is not really what I'm trying to get at. I suppose it's difficult to put a finger on because the two processes (in the head and in the world) are usually heavily interleaved. Even if some people tend to one or the other, there would not be any really sharp distinctions between one and the other and the whole thing would change over time, in different situations and so forth. Dreaming (including daydreaming), for example, is at one extreme, while formula-one driving is probably near the other.

Preoccupation about the eye is a borderline case. It is thoughts about the tools of real-time observation. It falls mid-way on the dreaming/formula-one spectrum. I wonder whether an AI would have come up with that idea. It seems a somewhat unusual series of thoughts that have led me here.