Arent we all slowly dying...?

But yes, if I remember correctly it was explained that she returend blind from the life stream, yet uses her aether (aka: her life energy) to replace her sight - if I havent dreamt this part it was even explained that shes not actually seeing the world as we do bute more the aether in it (I always picture it as some sort of heat-vision). This is ofc draining her life force itself, so ultimatly her life maybe shorter than it would be without this.
(...seeing how the warning came from Matoya, a woman so old that you wonder if she dug that cave shes living in herself a thousand years ago, I try not to worry to much about it and hope that the effect wont kill her within the next 2 years but rather in the next 20...)