Iron is the most common intraocular foreign body, the foreign body in the lens can form a limited cataract, if the iron foreign body is small, it can exist in the crystal for many years without obvious reaction, iron can oxidize in the eye and gradually spread in the eye, forming ocular rust deposits, including rust deposits in the cornea, iris, lens, and retina, eventually leading to blindness, the rust deposits in the eye are related to the size and location of the intraocular foreign body. Larger and posterior foreign bodies tend to migrate to the posterior segment of the eye. Lens rust deposition is a clinical symptom of traumatic cataract. Direct or indirect mechanical injury to the lens can produce cloudy changes, called traumatic cataract. Patients are most often seen in children, young adult males and warriors. How is iron deposition in the lens diagnosed? 1. History of trauma. There are signs of trauma to the eye in this disease. 2, vision loss. The patient has blurred vision, monocular diplopia or hyperopia, or a rapid decrease in visual acuity to light perception. 3. Clouding of the lens. The clouding is limited or diffuse. The clouding occurs mainly in the cortex, but also in the nucleus, which is less common in the capsule, because the capsule is thin and elastic. After injury, the cystic membrane is ruptured and rolled out or folded in. The thickening of the capsule or the scarring of the epithelial proliferations results in a “capsule clouding”. Crystalline copper deposition is a clinical symptom of traumatic cataract. Direct or indirect mechanical injury to the lens can produce cloudy changes, called traumatic cataract. Patients are most often seen in children, young adult males and warriors. There are three common types of cataracts caused by blunt contusions, blast injuries, and penetrating eye injuries. The disease has a variety of names due to the factors causing the injury and the local presentation. Most cases can be described with a clear history of trauma, but it is important not to overlook traumatic cataracts that “deny a history of trauma”, especially in infants and children. In the initial stage, there are small brownish-yellow dots under the anterior capsule of the crystal, and in the later stage, there are brown rust spots under the anterior capsule, which can be detected only after the pupil is dilated in the initial stage. Even if the cataract is removed, the vision cannot be restored quickly.