WITH MORE THAN 50% DAMAGE, a leaf that had more than 50% of its surface damaged is not efficent its photo cells are badly damaged, so instead of the plant wasting power to keep those really (50% or more) damaged leaves, you just clip them and let the plant work towards growing new leaves. If its really bad just clip the worst of the damaged leaves. Again with the 50%. if you remove more than 50% of the plants leaf matter it will go into shock, so you have to be careful when removing all those damaged leaves again, try to clip the MOST badly damaged leaves first.