My experience as a cataract surgeon is extensive and complication rates are published on NHS Choices at the following webpage:
Cataract surgery risks under Mr Shafiq:
This is information on posterior capsule rupture, the commonest type of surgical complication. In my case it hovers between 1 complicated operation per hundred operations to one in 200 hundred operations. This figure is very low and means that 99 operations in every hundred proceed as planned, without complication.
Infection is extremely uncommon, but can cause serious damage to the eye if it occurs. The quoted risk is of a sight threatening infection occurring 1 per 1000 operations, although my infection risk is lower than this taking into account several thousand cataract operations.
Other problems: there are other problems that can limit the outcome of cataract surgery, which are possible. In general more than 95 in a hundred operations will lead to improved vision.
If there specific risks associated with your eye, I will discuss these prior to any operation, so that you are aware of the risks and benefits .
Overall, it is an excellent operation!