Very rarely a patient might get a corneal abrasion after cataract surgery. This can come either from a rupture of a bullous keratopathy (which looks like a blister from inflammation that occurs under the outer epithelial layer), or from the eye opening under a pressure patch and being scratched by the patch.
The above photo is 4 days after surgery. The epithelium has grown over the abrasion and the edges are now fusing together. The patient will feel a foreign body sensation until this is totally healed. It may take about a week or so until it heals completely, during which time the vision will be blurry. But ultimately this patient will see just as well as if the abrasion never occurred.