Hot weather does not usually cause blurred vision, but blurred vision can be caused by iritis, glaucoma, cataract and other reasons. 1. Iritis: It is mainly caused by various pathogenic bacterial infections, trauma and systemic diseases. Due to the stimulation of inflammation, patients may have symptoms such as eye redness, eye pain, photophobia, tearing, blurred vision and vision loss. 2. Glaucoma: It is a group of diseases characterized by characteristic optic nerve atrophy and visual field defects as a common feature. It is mainly caused by elevated intraocular pressure, heredity and developmental abnormalities. Due to the lesions in the eye, it often causes eye swelling, eye pain, photophobia, blurred vision, iris vision, night blindness and other symptoms. 3. Cataract: It is a visually impaired disease caused by a decrease in transparency or a change in the color of the lens. It may be caused by aging, eye surgery, tumors, etc. Patients may suffer from vision loss, abnormal color vision, blurred vision and other symptoms. It is recommended that patients with blurred vision go to the hospital in time and role for treatment to avoid delay.