The current cataract surgery is microscopic cataract ultrasound emulsification plus IOL implantation, which is very different from the past. The incision does not have sutures, but closes by itself, so the foreign body sensation in the eye is not related to the sutures. Generally, it may be related to the following reasons. The first one is that the conjunctiva at the incision site has an inflammatory reaction or is more edematous, which will cause irritation and a foreign body sensation in the eye. The second is damage to the corneal epithelium during surgery, or more severe damage to the corneal endothelium. In this case, the cornea will become edematous, and keratitis symptoms of photophobia and tearing and foreign body sensation will occur. The third type is that after the crystal is implanted in the eye, after all, the crystal is a foreign body that has a rejection reaction and causes an inflammatory reaction in the eye, resulting in inflammation in the whole orbit or inflammation and irritation in the whole eye, which is more serious, and then there will also be foreign body sensation.