Stop curling you lashes and see if the condition improves.
Dr. O.
If there's nothing medically wrong (and you should find out first), you could try one of the eyelash growers. They may also help curl your lashes.
Note: These may be made with prostaglandin, or they may be made with a prostaglandin "analogue", or no prostaglandin. I looked up "prostaglandin analogue" and got a list with about a million chemicals. I'm probably not allowed to recommend a brand here, but I'll try code: The one I use, and it works very well, starts with L-i. I don't work for the company, invest in the company, or even know where they're HQ'd. Some brands are more irritating than others.
If you get a prostaglandin-based eyelash grower in your eyes consistently, it's possible that it will turn your irises brown. I have blue eyes & have been using it for about 9 months with no problem of that type so far.