I Too have worn contacts and have monovision. Am over the seventy-five mark and can still thread a needle without any help from add glasses. I sometimes close the distance-vision eye and it helps. There is a more than 4 diopter difference in correction for near vision. There is a certain amount of determination that has to take place. Worked as a optometric assistant for over 20 years and taught lots of patients to wear CL, and know that from experience.