What decides how good/poor near vision is after cataract surgery? (Distance IOLs)

I would like to know this as well.  My understanding was IOLs last for a lifetime and do not develop cataracts.  What you can get perhaps are other eye diseases which could impact vision.  Or PCO which can be cleared by a laser procedure (YAG)

Your near vision shouldn't change much if at all a few months after the cataract surgery has healed.

The natural lens prior to cataract surgery gradually gets stiffer and causes the gradual need for higher near vision glasses from age 40 and beyond.  Usually start with +1 or +1.5 reading glasses in your 40s, and move to +2 in 50s, +3 in 60s or 70s.

But after cataract surgery, what type reading glasses you will need depends on what refraction level your eye ends up at after the IOL is implanted. Also depends on the type of IOL, since some premium IOLs can offer some closer range than distance vision (Symfony, multifocals, Crystalens, etc).  But with a monofocal IOL set for good distance vision, probably the stronger reading glasses would be needed +2 to +3 especially for very close up reading and fine print.  For intermediate distance (computer screen, 2-3 feet away) a +1 or so would work.

Google Cataract surgery: Will my vision deteriorate after cataract surgery? It says:

"No, your vision generally doesn't deteriorate after cataract surgery unless other problems arise, such as macular degeneration or glaucoma.

In cataract surgery, the eye doctor (ophthalmologist) removes the clouded lens from your eye and replaces it with a clear, artificial lens. This lens is very durable and should last for the rest of your life. Sometimes the capsule that holds the artificial lens becomes cloudy after cataract surgery. This can affect your vision. An eye doctor can use a laser to make the lens capsule clear again.

Most people use glasses, at least some of the time, after cataract surgery. After your eyes have healed from surgery, your doctor may recommend prescription eyeglasses."

So I take that to mean if you don't need glasses right after the surgery, you won't need them later on either.

There are 2 parts of defining the day vision after a cataract surgery:

1. The best corrected distance vision with glasses

2. The prescription (spherical and cylinderical corrections) required to achieve the best corrected distance vision.

The prescription for reading glasses is typically +2.25D or +2.50D added to the distance prescription.

There can be lens-dependent night vision issues such as glare, multiple circles or halos, which can be there even if the day vision is good.

I wear +2.25D when I need to read my cellphone