I would be sure to NOT breed him. Cameos have had a long history of blindness that has pretty much been bred out now. I do not believe I have seen a Cameo go blind but the history is still there. There is also a thing called Progressive Pied where a bird will turn white over a few years. It is very common in Australia and they are quite pretty but those here in the US also have a history of going blind so we do not perpetuate them here. The most common was a Bronze Progressive Pied that had most of the problems.
I recently bought out a large breeder and acquired a Peach Pied hen that is also turning white. Her back is almost completely white and when I asked the last breeder of that bird he was shocked at the transformation. I am not going to breed her as she is showing signs of going blind.
View attachment 2868766
Now I have another hen that has turned white. She and her sister have looked like normal Peach BS until this molt. It is normal for sex-linked birds to sun fade so I did not take any particular notice when she lightened up but with this molt, she has come back nearly totally white save for her wings. In this picture, she is standing behind her sister that is still the normal BS pattern.
View attachment 2868769View attachment 2868770
Both of these hens turning white are completely unrelated, the yearling Peach BS split Bronze in the last pic is not showing any sign of impaired vision but she is young and may yet develop sight problems.
Suppressed genes can pop up at any time and at any age but when I suspect an oncoming genetic problem I error on the side of caution and do not perpetuate the lineage.