Cataracts can cause an increase in intraocular pressure. Cataracts develop through four stages, including the initial, swelling, maturation and overmaturation stages. When a patient is in the swelling stage, the patient’s lens will grow and cause changes in the structure of the eye, resulting in glaucoma, which will increase the pressure in the eye. When patients have elevated IOP, they mainly manifest as loss of eye vision, eye pain, blurred vision, and even headache, etc. When these symptoms appear, they should go to the hospital in time for reasonable treatment. When cataract appears with increased eye pressure, it is called cataract secondary glaucoma. At this time, patients may be able to lower the eye pressure through eye drops, or if the patient’s eye pressure is still not controlled after eye drops, surgery is taken, and nowadays, cataract removal surgery is mainly taken. If the patient has anatomical abnormalities of glaucoma and cataract at the same time, during the surgery, not only cataract surgery but also glaucoma surgery is given to the patient, and this surgery is cataract combined with glaucoma surgery. Most patients, although they have cataract secondary to glaucoma, do not have glaucoma factor themselves. In this case, only cataract but not glaucoma surgery is needed to treat high eye pressure and improve the symptoms of high eye pressure as well. Therefore, although cataracts can cause glaucoma and high IOP in the process of development, timely treatment will give good results.