Cataracts have the potential to cause eye swelling and pain as they develop. Cataracts are a very common eye disease in ophthalmology. Typically, during the development of cataracts, there is a risk of eye swelling secondary to increased intraocular pressure. The swelling stage of cataract will cause the anterior chamber to become shallow, the angle of the chamber to become narrower, and the angle of the chamber to close and induce an increase in intraocular pressure, which causes eye swelling and pain. In addition, if cataracts are not treated in time, they can develop into the over-ripening stage, which can also cause an increase in intraocular pressure and lead to secondary glaucoma, causing eye distension. When cataracts cause eye swelling and pain, you should go to a regular eye care provider and get prompt treatment to avoid delaying your condition.