Congrats on your niece! I apologize its not starting as we all imagine it should.
Microphthalmia is small eyes and anophthalmia means no eyes. Sometimes either or can be linked to a syndrome and there may be other genetic issues. Sometimes its the only genetic defect.
If your niece has both of her eyes, but they are malformed its microphthalmia. If there aren't any eyes its classified anophthalmia. If the docs are saying her retinas did not fully develop then there may be eyes. My son, now 7yrs old was born with bilateral microphthalmia and we did not know until the day after he was born. He too never opened his eyes and when he did they looked strange. He did not have any syndrome and as far as we can tell it was just a fluke. If this was not a worry during the pregnancy and ultrasounds weren't done to try and detect it, then they wouldn't know to look for it. When I had my second son, I went to a maternal fetal specialist for an ultrasound to measure eye sockets etc.. Which appeared of normal size at that gestational age and his eyes are fine.
Please let us know how your niece and family are doing. Feel free to email me:
mballard@bex.net if you have any other questions. I hope it helps alittle.
Michelle