Not sure if this has been suggested before but i used the board search to try and see if anyone did and couldn't find something similar so here goes.
I would like to suggest a Double Pupils Mutation, where the mutated lion has two pupils in each eye.
It would vary if the pupil shape is different. The draconid eye color would have two slitted pupils in each eye, all eye colors with the usual round pupils would have a smaller round pupil next to the main larger pupil.
In real life when your pupil is an abnormal shape it doesn't affect your vision per say, so unlike the blind mute i believe a lion with the double pupils mutation would still be able to hunt or parol.
But if it is considered an Iris Coloboma then it would indeed affect vision, although not as severely as blindness, and perhaps could affect hunt or parol, perhaps with lowered netted rewards for a double pupil muted lion(if it is perhaps it could be called the Iris Coloboma mutation instead)?

I don't necessarily know if it'd show up in explore, but if it did it'd be a nice way of introducing a mutation that affects the explore aesthetic.