Well sure, not ‘Low Vision’, but we all have the experience of our vision being inadequate for some tasks. It’s useful to consider those situations, as it can provide insight when we have patients whose vision is inadequate for other tasks. Consider them ‘lessons in empathy’.
There are probably a lot of (younger) readers who have never encountered one of these. It’s a microfiche reader. In the days before extensive digitisation of resources, libraries would deal with the problem of storing vast quantities of newspapers, magazines and other documents by taking very high resolution photos of them, and then storing the miniaturised slides of those photographic images, which took up only a fraction of the space.
The reason I’m showing this device is that those images were truly tiny, each page much less than a centimetre high. There was no way our eyes could see such fine detail, so we used a microfiche reader to project a highly magnified image of the slide on to a screen. This was how we dealt with encountering detail that was too small — we used a device that made it bigger.
Next situation. We all know this one. When what we’re looking at is too dark, we find a way to make it brighter. Lighting design is all about making sure we have adequate light in our day-to-day lives, but our standards are calibrated around normal vision.
This one’s not so common for most of us, but very common if you’re a historian, who often encounter faded documents. This sort of thing needs the big guns — a magnifier might help a bit, and bright light might help a bit, but what you really need is a computer that can scan the image and then enhance the contrast. This is the most effective way of dealing with a document that is too pale. We use a special device that can make it bolder.
Up until this point, the problems have been a matter of a mismatch between stimulus and sensitivity. The illumination is lower than our retina is designed for, or the object is too small for our retinal resolution. The issue is generally solved by appropriate design — we illuminate our rooms to a certain standard, we don’t use print below a certain size. Loss of central field integrity is different though. It’s not merely a mismatch, and we can’t really design around field loss.
There are few circumstances in which we can get insight into the experience of macular field loss, but this is one most will have encountered. Afterimages from a photo flash (damn those paparazzi, they won’t leave us low vision optometrists alone!) or reflections of the sun off shiny surfaces, which then get in the way of everything we look at for a while. This is one of the few times when we get to experience having a macular scotoma, so make the most of it when it happens. Look at people’s faces, then experiment with eccentric fixation. Try reading fine print. Take note of how bloody annoying it is, and then take a moment to count your blessings that in ten minutes your scotoma will be gone, unlike your patient with AMD who has it forever.