Having had said operation, you'll find that the lid was held open during the peration by a multi-fingered clamp affair. I had some swelling due to that, but went away in maybe 3 weeks. Some friends report, as Sqad states, that swelling or weakness continued for a while.
What you're feeling is scar tissue formin over the minute incision required to withdraw the previous natural lens and insert the new one. My experience is that the area can still be felt occasionally even some ten years later. Especially if you have dry eyes, which is also not uncommon.
You may notice, if you press gently on the eye, you can actually "see the new lens. I can even see the stabilizing "wires" coming out of it. My opthamologist says maybe, maybe not... I have no other explanation for the phenomena, however.
Lastly, I expressed surprise to my opthamologist when the cataract was diagnosed since I felt I was too young for such an event. He said some cataracts are caused by age but many are caused by eye injury and eye professionals can tell the difference. I had, apparently, injured that eye some time in the past that I don't recall...