If I may, I think Chirs' reference may be to that person who has cataract surgery (removing the clouded lens) who, for whatever reason doesn't have the additional lens replacement segment. I've known a couple of older people whose overall eye condition prohibited the lens replacement and were issued corrective glasses instead.
Both report less than satisfactory vision resluts.
However, cataract surgery with lens replacement is almost fool proof (depending on number of adjacent fools available) and reuslts in nearly 20/20 vision for all. The only problem being how nearly the opthamologist has measured the eye to predict the required replacement lens.
In my case, both eyes were done within just a week and recovery time was apleasant 2 hours accompanied by excellent tea and cookies (your biscuits) provided by the opthamologist. Vision was nearly perfect. The opthamologist suggested that if I had a minor corrective action via lasiks the vision in the left would be perfectly 20/20 as it was already in the right. Since I've a concern about laser surgery, I didn't elect to have that done and am happy with the results.
One thing almost all replacement lens patients will report, though is that, although the replacement lens is stabilized with small "stabilizers" at each edge of the lens, the lens can move slightly right or left. I notice that if I shift or move my eyes quickly without turning my head a shadow can momentrilly be seen as the lens readjusts to its position. No big deal and one soon gets used to it...
I drove a car within one day perfectly comfortable that I posed no danger to myself or others...