Can I get a 20/40 requirement waiver after cataract lens replacement?
If you are a member of or join AOPA I recommend consulting AOPA member services for help with questions like this. I have consulted them multiple times and they always get a good answer for me or set me in the right direction.

Of course you can consult an Aviation Medical Examiner (AME) first but I recommend you figure out what you need to do and go into your AME knowing you’ll pass the medical exam... once you’ve failed it can be a nightmare to get your medical back and take a long time (and cost lots of money).

Source: I’m a pilot who has used this service of AOPA before