What Should I Do If My Son Developed Redness And Itching In His Right Eye After Using Cromal Forte Drops And Eye Patching?

My son is 7 yrs age, he has reddish in his left eye and rubbing. We consult with the opthalmologist adviced to give 2 drops of Cromal Forte in both eye and get in Right eye Cly( -1.75) V/A 6/9F N6, Axis 165 and in left eye Cly (-1.00) V/A 6/9FN6 Axis 180 also use eye pathch in left eye for 6hrs/day. But all we had done, his right eye began to red and itching. Please give me suggestion what will I have to do right now?