Tetrachromats

It has been discovered that some people, probably a tiny proportion of women, can see extra colours in the red-orange range. There are devices that are designed to drive kids away with high pitch sound that older people cannot hear. We have long known that some people can't assimilate words as well as others. Autism deprives you of the ability to read the emotions of others. Then, of course, there are the blind and the deaf. 

What other blindnesses are there that we don't yet know? 

Comments

[Velvet Snoutingdingle]

So far unconfirmed, but I read an article which says that our eyes yellow as they age, narrowing our sensitivity to near UV.