Oct is the abbreviation for optical coherence tomography, a commonly used eye exam that is used to check for retinal disease and structural abnormalities in the anterior segment. The retina is located inside the eye and cannot be observed from the outside. When the retina suffers from a disease, it needs to be observed by means of funduscopic examination, and the oct examination, also known as coherence tomography, is a very fine funduscopic examination, which is capable of observing the subtle lesions occurring in the retina, and it is an effective means for the diagnosis of retinopathy at present. In addition, there is also anterior segment OCT, which is used to check whether there is any abnormality in the patient’s anterior structures, such as blockage of the atrial angle and corneal foreign body. It is recommended that patients with abnormal OCT examinations should seek prompt medical attention to evaluate their condition and choose the correct treatment under the guidance of their doctors.