True blindness.

The Night Planted Orchard is about colour but as the name might suggest, it's also about the loss of light:  the waxing and waning of colour through the year, or the spectrum of colour that we can and cannot see, or even the inner blindness that afflicts us. In the last few years I've become long sighted. At times it annoys me half to death, but then I remember where I am on that spectrum and feel ashamed.

Most humans only have three light types of colour sensor in their eyes. A tiny proportion can see a second range of red colours. Many animals can see fewer colours than us. Cats and dogs have a far richer sense of smell than sight and when a dig sits and seems to stare at a view, as mine often does, it is actually sensing a scent landscape. If that seems strange, imagine having the eyes of a dragonfly. A dragonfly can see far more colours than humans in whole extra ranges and their sight includes the ability to sense the polarisation of light. What kind of vision would that enable?

But there are other darknesses too. I have an aunt and uncle who have both gone blind. My uncle showed me so much of the world, and he can't now see any of it. I remember my aunt's eyes, stern but with the kindest of twinkles and always penetrating. Eyes that could peer into me, now always searching. Another aunt has passed into that even stranger bewildered twilight of dementia where she cannot see us and, through cowardice or unbearable sorrow, we cannot see her either. She is gone now, and so is my blind uncle. Whether it was imaginary pirates through an old telescope or the vision if a steam train thundering past, or bonfires and fireworks, they taught me to see and their passing breaks my heart.

No. Having to find a pair of glasses to read is not blindness, not by a damned sight.