Andrew Leland

But then a week will go by, I get used to it.

I don't feel so blind anymore.

This experience of super gradual vision loss has given me time to think about what blindness is, which might seem like an obvious question.

Blindness is the absence of sight, but it's actually more complicated than that.

Trying to define blindness can start to feel paradoxical.

There's a paradox that's useful in thinking about blindness.

It's called the paradox of the heap.

Let's say you have a heap of something, like sand or marbles or goji berries.

Now, imagine I take a single little goji berry off of the heap.

Is it still a heap?

Okay, what if I remove a second tiny little goji berry from the heap?

Obviously, that is still a heap also.

But the ancient Greek philosopher wondered, at what point is it no longer a heap?

How many goji berries do I have to remove?

Is it still a heap when there's only 10 left?

Five?

Vision works this way too.

How much vision do I need to lose before I can legitimately call myself blind?

I saw this photo online the other day.

The image circulated with the caption, if you can see what's wrong, say, I see it.