refractive error
Introduction
Refractive error introduction Refractive error refers to the fact that when the eye is not used for adjustment, the parallel light passes through the refractive power of the eye, and can not form a clear object image on the retina, but is imaged in front of or behind the retina, including farsightedness, myopia, and astigmatism. There are many reasons for refractive errors. Genetic factors are very important reasons. Of course, unreasonable use of the eye is also a reason that cannot be ignored. Children are in a period of growth and development, and they do not pay attention to eye hygiene. For example, reading and writing postures are incorrect. Or the light is not good, causing the distance between the eye and the book to be too close, or reading for too long, or walking, reading a book by car, etc. can cause excessive eye fatigue and promote refractive error. basic knowledge The proportion of illness: 0.06% Susceptible people: no specific population Mode of infection: non-infectious Complications: retinal detachment
Cause
Refractive error
Myopia (25%):
Mild or moderate myopia, except for distant objects, there are no other symptoms. When working at close range, you can see small targets without adjustment or less adjustment, but it is convenient, but at high myopia, work. When the target distance is very close, the two eyes are too inward to gather, which will cause the use of excessive rectus muscles and visual fatigue symptoms.
Hyperopia (25%):
The visual acuity of hyperopia is determined by the height of its hyperopia and the strength of the adjustment. Mild hyperopia can be overcome with a small part of the adjustment force. Far and near vision can be normal and generally asymptomatic. Such hyperopia is called hyperopia. Recessive hyperopia, slightly more hyperopia or poorly regulated, so far, near vision is not good, these remaining parts that can not be fully compensated by the role of regulation is called dominant hyperopia, the combination of recessive hyperopia and visual For general hyperopia, hyperopia is prone to visual fatigue due to long-term stress regulation.
Visual fatigue (30%):
After reading, writing or working close-up work for a long time, there may be handwriting or blurred goals, dry eyes, heavy eyelids, fatigue, eye pain and headache. After a short break, the symptoms are obviously reduced or disappeared. Generally, afternoon and evening are the most common. When severe, even nausea, vomiting, fashion can be complicated by chronic conjunctivitis, blepharitis or stye recurrence.
Prevention
Refractive error prevention
1) You should always do eye exercises, press the temples, or close your eyes to keep your eyes closed. Keep your eyes closed and you can rest your eyes and rest your brain.
2) Don't lie down and read a book. Don't look at it while walking. Don't read a book when you are in the car. When you read a book, you usually have to get up every hour, and use your palms to cover your eyes and gently massage. Then look into the distance and look as far as possible. It is best to look at green plants, because green plants can absorb ultraviolet light from strong light, reduce or eliminate the harmful effects of ultraviolet rays on human eyes, and give the eyes a comfortable feeling.
Complication
Refractive error Complications
1. Retinal detachment can occur in high myopia.
2. Hyperopia can cause chronic conjunctivitis, mumps and blepharitis.
3. Astigmatism can be complicated by gastrointestinal symptoms.
Symptom
Refractive error Symptoms Common symptoms Visual impairment Visual field of vision changes Fatigue tension Nasal vision loss
Clinical manifestations of myopia: mild or moderate myopia, except for distant objects, there are no other symptoms. When working at close range, you can see small targets without adjustment or less adjustment, but it is convenient, but at height. Myopia, when the target distance is very close, the eyes are too inward to gather, which will cause excessive use of the medial rectus and visual fatigue symptoms.
Clinical manifestations of hyperopia: the visual acuity of hyperopia is determined by the height of its hyperopic diopter and the strength of the regulation. Mild hyperopia can be overcome with a small part of the adjustment force. Far and near vision can be normal, generally asymptomatic. The farsightedness is called recessive hyperopia. The slightly hyperopia or the adjustment power is slightly insufficient. Therefore, the near vision is not good. The remaining part that cannot be fully compensated is called dominant hyperopia, recessive hyperopia and visual. The total combination is called total hyperopia, and the hyperopia is prone to visual fatigue due to long-term adjustment of tension.
Symptoms of visual fatigue refer to reading, writing or working close-ups for a long time. There may be blurred writing or target, dry eyes, heavy eyelids, fatigue, eye pain and headache. After a short break, the symptoms are obviously reduced or Disappeared, this symptom is usually the most common in the afternoon and evening, when severe, even nausea, vomiting, fashion can be complicated by chronic conjunctivitis, blepharitis or stye recurrent.
Clinical manifestations of astigmatism: those with low diopter may be asymptomatic, and slightly higher astigmatism may have vision loss. Look far, near is not clear, seems to have ghosting, and often has visual fatigue symptoms.
Examine
Refractive error check
The refractive examination includes subjective examination and objective examination:
Subjective examination method: 1. According to the preliminary analysis of visual acuity judgment, the refractive property method, 2. insert optometry, 3. cross-column and astigmatism optometry, 4. cloud method, 5. astigmatism optometry, 6. Pinhole sheet and slit sheet inspection method, 7. Laser speckle pattern method.
Objective examination method: 1. Direct ophthalmoscopy, 2. Retinoscopy, 3. Band photorefraction, 4. Corneal, 5. Auto optometry.
Diagnosis
Refractive error diagnosis
1. Myopia needs to be differentiated from pseudomyopia.
2. Hyperopia needs to be differentiated from papillitis, myopia, presbyopia, and right vision.
