Prior to cataract surgery, my near-sighted vision was near perfect; I could read without glasses. The surgeon implanted lenses with the same power as my natural lens. But one eye is slightly off by -.50 to -.75. Should I have the lens replaced?

07 Dec Prior to cataract surgery, my near-sighted vision was near perfect; I could read without glasses. The surgeon implanted lenses with the same power as my natural lens. But one eye is slightly off by -.50 to -.75. Should I have the lens replaced?

Probably not.

There are really two issues here: 1) Why is it, to your surprise, you now need reading glasses and you didn’t before your cataract surgery? 2) How easy and safe is it to remove and replace an intraocular lens (IOL)?

Nearsighted (myopic) people enjoy one single advantage over other, normally sighted people: For the same reason they cannot see off at a distance without glasses, their default focal point is at near. This means they do not have to accommodate, i.e. use the muscle surrounding their natural lens to squeeze it into a different shape better suited for near vision. When people become presbyopic in middle age, it is due to the natural lens hardening which creates resistance to the muscle. But since a nearsighted eye doesn’t need to accommodate to see up close, you can still read (at least without your distance glasses on). As the natural lens ages further, it slowly discolors and becomes hazy. That is the cataract.

If your doctor did not demonstrate and explain in advance what would happen, and if he selected an IOL prescription set for distance focus (which is what most people want), you are going to lose that nearsighted advantage for reading!

The second issue, then, is whether it would be a good idea to surgically remove and replace the IOL with one having a different prescription. While this can indeed be done, you must remember it is a new operation and so doubles the possibility of complications. One of my most upset patients had something similar happen, insisted I remove and replace the IOL, but suffered a retinal detachment with serious loss of vision! Of course such an occurrence is very, very rare but this didn’t make him feel any better!

I don’t know the specifics of your particular case, so I can only speak in a general sense. But I would be skeptical about performing an IOL exchange for such a small degree of residual myopia.