"Can you tell me, my daughter was born with a birthmark on her eye (on…

"Can you tell me, my daughter was born with a birthmark on her eye (on the white part)? See photo below ? Doctors in the maternity ward assured me it would go away, the pediatrician came and said it would go away. I have an appointment with an ophthalmologist next week. Has anyone else experienced this? Did it go away on its own or was there any treatment?"