I had some flickering for a couple months following cataract surgery I had on one eye only, using a monofocal IOL, and then only when in bright sunlight or under fluorescent lights. It's pretty much resolved itself since. Regarding the glasses, you'd have to describe if both of your eyes were corrected by the IOLs for distance vision or if a monovision approach was used with one eye set for distance and the other for close up. Readers are cheap though, and if both of your eyes were set for distance correction try a different strength than your old ones until you find one that works. I use readers as needed over contacts, and there is only one strength that works correctly for me out of all the ones offered.