The causes of long eye axes usually include myopia and scleral collagen disorders, which need to be treated as soon as they are detected. The so-called eye axis refers to the anterior and posterior diameter of the eyeball, and the causes of eye axis lengthening are mainly related to myopia and scleral collagenous tissue disease. Myopia can be categorized into curvature myopia and axial myopia, and axial myopia is caused by the excessive length of the eyeballs. As the length of the eyeballs becomes longer, the patient’s myopia will gradually increase. In addition, the length of the eye axis is also generally related to systemic collagenous tissue disease or systemic connective tissue disease, the above diseases will cause the local scleral collagen tissue to gradually soften, and then constantly undergo dilatation, and ultimately cause the eye axis to become longer. If there is an unexplained change in the length of the eye axis, it is recommended to go to the hospital for examination.