Swelling and pain in the eyes of patients are usually caused by glaucoma, visual fatigue and blepharitis. 1. Glaucoma: Due to the abnormal functioning of structures such as the atrial angle and trabecular meshwork inside the eye, patients with glaucoma are unable to expel the fluid generated inside the eye, and a large amount of fluid accumulates inside the eye, leading to an increase in intraocular pressure, which can lead to eye distention, eye pain, vision loss and other symptoms, and can also be accompanied by nausea and vomiting. 2. Visual fatigue: After using the eyes for a long time at close range, the ciliary muscle inside the eyeball will contract for a long time and cause spasm, which can cause visual fatigue, and the patient may have symptoms such as eye swelling, pain and soreness. 3. Blepharitis: Blepharitis refers to suppurative inflammation of the eyelid glands. Under the stimulation of inflammation, patients may experience redness, swelling and pain in the eyelids, accompanied by photophobia, tearing and other discomforts. Patients with significant eye swelling and pain are advised to seek prompt medical attention to assess their condition and follow medical advice.