I have been diagnosed with benign concentric annular macula dystrophy im in my 30s can it start at this young age and what kind of sight loss can i expect?

BCAMD: It starts around age of 30. Family members can also be affected so they should be checked. The dystrophy is not very well described because it is rare. But based on prior cases most preserve good day time vision but may experience night vision and color vision changes. The changes start a decade or two later, so the changes are slow to start. Continue follow up with retina doc. Good luck.