I’ve heard that if you get Glaucoma, a disease of the eye, the symptoms are hard to notice at first. It damages your peripheral vision and, if left untreated, can cause blindness.

I found myself wondering how people feel in this transitory phase, with their peripheral vision being worn away imperceptibly, like cliffs that are worn away by the sea, unnoticed until the landslide.

Apparently it takes a long time to notice that the change in what you’re seeing. Then people report having tunnel vision, the edges of their line of sight having already been irreparably worn away.

At first, it must be almost impossible to notice. Maybe there’s a period in the process of losing your vision where you simply find yourself more surprised by everything. Your cat brushes against your leg, making you jump. This happens the next day, and the next. You begin to wonder whether you are distracted, nodding off. Maybe you put it down to being less alert, you have a second Pro Plus in the morning, and all this does is make your limited field of sight even more vivid in its limitation, like investing in a HD television set that’s a couple of inches narrower.

You barely notice the change except that your cat brushed against your leg again today and again you had not seen her and you spill your coffee. You walk outside and your neighbour, who you hadn’t seen gardening, despite walking straight past the fence, calls out hello. You wave back and nervously continue on into your car. You almost back into a cyclist who came out of nowhere.

In the meantime, what it is that you CAN see captures your attention in a way that would have been impossible before. You hadn’t seen the neighbour gardening out of the corner of your eye, and so you noticed the robin that stopped to perch on the roof of the shed. You didn’t see the cyclist which meant that you turned too soon and you caught a glimpse of your child’s birthday card to you through the living room window. It warms your heart.

By the time you notice that there is something wrong, that something has changed and that you don’t like it, you have lived your life according to what you could no longer see, according to what you now have the capacity to notice.