I acknowledge the worry but do not think it apply's; we mess with nature all the time we stop tumors, remove cancer, use surgery from all those things you could argue that it interferes with nature. science decides what is a disease, the definition is: an abnormal condition that harms the body or mind and stops normal functions. we have world wide standards about what clasifies as a disease. brown eyes do not limit normal functions, neither does light skin or a normal intelligence. it isn't hard to draw a line and to demonstrate i will draw it: Gene editing must only be used on conditions that are distructive to someones live either ending it completely or lowering the quality of life to where even the basic needs as food, water, shelter, securate cannot be given in a normal way.