In terms of human physiology, the sclera is composed of collagen tissue, and iron in the body is an important cofactor in the synthesis of collagen. If the body is deficient in iron, the collagen synthesis will be insufficient, and the sclera will become thin and cannot effectively cover the brownish-black choroid in the eye, which will be light blue when viewed under natural light. At the same time, there are many diseases that cause blue sclera. Patients with blue sclera need timely diagnosis and early treatment. Diagnosis of blue sclera: 1. Observe and ask the patient (1) Observe the color of the patient’s sclera. Normal sclera is porcelain white, while patients with blue sclera have a uniform bright blue or blue-gray sclera appearance, and slightly pale white outside the corneal rim. (2) Ask the patient whether anemia is present. Understand the sequence of blue sclera and anemia. 2.Instrumental examination (1) Routine blood test Routine blood test is the most routine examination item. By observing the changes in blood quantity and morphological distribution, etc., we can determine whether the patient has anemia or other conditions. (2) CT scan CT scan takes the traditional X-ray imaging technology to a new level, and CT scan can build a complete three-dimensional computer model of the inside of the human body. Doctors can even examine a small slice of a patient’s body to pinpoint specific areas. Doctors can examine patients with blue sclera in detail.