Strabismus and diplopia are both common problems in outpatient eye care. If you are a patient or parent who is seeking medical attention, perhaps my answers can provide you with some help. 1.What is strabismus? Strabismus is a condition in which both eyes cannot look at the same target at the same time, and when one eye looks at the target, the other eye becomes deviated. Sometimes parents find that the child’s two eyes are squinting together to gaze at the object (squinting), which is not strabismus, but is generally called lateral vision, mostly due to bad habits or refractive error. 2. According to the direction of eye position, strabismus is divided into the following four categories: (1) Internal strabismus: the eye position is oblique inward, generally known as “cross-eyed”. (2) Exotropia: the eye position is skewed outward, commonly known as “oblique white eyes”. The most common type of exotropia in children is intermittent exotropia, which is intermittent and constant. Intermittent exotropia is a strabismus that is sometimes orthotropic and sometimes exotropic, especially when tired or distracted, and can be controlled to an orthotropic position with reminders. Children with this type of strabismus often close one eye in the sun, which is done to avoid diplopia caused by exotropia. If left untreated, intermittent exotropia will gradually develop into constant exotropia. (3) Vertical strabismus: the eye position is skewed upward or downward, and vertical strabismus is often accompanied by a tilted head, commonly known as “crooked neck”. Strabismus does not necessarily mean that the head is crooked, but a crooked head must be alert to strabismus. (4) Rotational strabismus: Rotational strabismus is generally not visible in appearance, and will only be detected after a specialist examination. 3.What are the hazards of strabismus? (1) It affects the aesthetics, which is the most intuitive understanding of strabismus by patients and their parents. (2) Strabismus can lead to the loss of stereo vision function. People with strabismus cannot work in aerospace, aviation, driving, medical and other fine operations, which will seriously affect their future employment and career choice. Therefore, it is emphasized that strabismus should be treated as early as possible to restore part of the stereopsis function. (3) Some types of strabismus can affect visual acuity and lead to amblyopia. 4.How should strabismus be treated? Most strabismus requires surgery. There is a type of strabismus that disappears after wearing glasses and does not require surgery; wearing glasses is the best treatment, and there are some strabismus that requires both glasses and surgery. It is wrong to blindly believe that strabismus can disappear with age. As soon as strabismus is discovered, you should go to the hospital for a professional eye examination to avoid delaying the best time for treatment. 5.Can I wear glasses to cure strabismus? There is only one type of strabismus called complete refractive adjustment internal strabismus that can be corrected with glasses. This kind of strabismus is caused by farsightedness and can be corrected by wearing suitable glasses. Complete refractive adjustment strabismus emphasizes the need to fully dilate the pupil with a slow dilating medicine, atropine eye solution or eye ointment, and the degree of hyperopia must be checked accurately, and the glasses must be of adequate prescription. Therefore, at the first visit for internal strabismus, the pupil must be adequately dilated with the slow dilating drug atropine. If the strabismus disappears after wearing glasses, no surgery is needed. The degree of hyperopia gradually becomes smaller with age, and when it is small to a certain extent. When the strabismus does not appear even after the glasses are removed, you can remove the glasses completely. And this type of strabismus must not be operated, if surgery, with the passage of time will become exotropia. 6.Why should I have strabismus surgery if the child has a crooked head? Crooked head is also called squint. There are two common reasons for a crooked head: one is due to squint called ocular squint and the other is due to abnormal neck muscles called muscular squint. Ophthalmic squint requires strabismus correction and muscular squint requires neck surgery. A tilted head can lead to facial asymmetry, with one side of the face being full and the other thin. Crooked head can also lead to scoliosis of the cervical spine and developmental deformities of the jaw. Therefore, if a child has a crooked head, it is recommended to see a strabismus specialist and an orthopedic surgeon as soon as possible to identify the cause and treat it as early as possible. 7.Is strabismus surgery safe? Will strabismus surgery cause vision loss? Strabismus surgery has a history of 150 years and is one of the safest surgeries. The surgery does not open the eye, so it usually does not affect vision, and you can see normally the day after surgery by opening the gauze, which basically does not affect normal life and has less risk. There are a few patients who will suffer from a temporary loss of vision due to visual disturbance after surgery, and the decreased vision can be easily recovered. 8.Is strabismus surgery only for the “squinted eye”? Strabismus is generally a two-eye problem. When the strabismic eye is looking, the opposite eye (the eye that is not normally strabismic) will show strabismus. Therefore, strabismus surgery is not only for the “squinting eye”, but sometimes for both eyes and sometimes for the eye that is not normally squinting. 9.Does general anesthesia for strabismus surgery have any effect on intelligence? General anesthesia is generally required for strabismus surgery in children, and general anesthesia has no effect on intelligence. Nowadays, in developed countries such as Europe and America, due to their high economic level, general anesthesia is also used for adult strabismus surgery. General anesthesia can provide patients with comfortable treatment, and patients will not have pain and fear during the whole surgery. 10.What is diplopia? Diplopia is the double vision. Diplopia is divided into monocular diplopia and binocular diplopia. Monocular diplopia refers to seeing an object as two images in one eye. Binocular diplopia is when an object is seen as two images by both eyes, but one image when viewed with one eye. The diplopia mentioned below refers to binocular diplopia. 11.What are the signs and symptoms of diplopia? (1) “Double vision”, if the patient complains of unclear vision in both eyes and clear vision in one eye, he/she may also have binocular diplopia. (2) Diplopia can cause great discomfort because the patient with diplopia tries to force to overcome the double vision, and the force causes visual fatigue, eye swelling and pain, headache, and even nausea and vomiting. (3) Various kinds of head tilting: diplopia is most obvious in the direction of the paralyzing muscles, so patients often adopt a compensatory head position to try to avoid the most obvious direction of the double vision, and there are various kinds of head tilting. 12, the relationship between strabismus and diplopia: If there is binocular diplopia, there is definitely strabismus. Although some patients with diplopia do not appear to have obvious strabismus, strabismus will be detected through strabismus examination. However, if there is strabismus, there is not necessarily diplopia. For example, congenital strabismus will not have diplopia. 13.Treatment process of diplopia: If there is an unexplained diplopia, first go to a strabismus specialist. After the strabismus specialist finds out which muscle or nerve is paralyzed, he or she will usually recommend going to the neurology department or the corresponding department for consultation. If the cause is not found, conservative treatment is given to nerve nutrition and other drugs to promote nerve and muscle recovery. If you still have diplopia after more than six months of conservative treatment, you will be given a trigeminal lens or surgery.