What are the symptoms of binocular refractive error?

A common manifestation of binocular refractive error is myopia, which can be divided into mild myopia and severe myopia. Some people may also experience various symptoms such as visual fatigue, so once these symptoms are discovered, they must be corrected in a timely manner.

1. Mild or moderate myopia has no other symptoms except blurred vision of distant objects. When working at close range, it is convenient to see small targets clearly without or with little adjustment. However, when people with high myopia are working, the target distance is very close and the two eyes are too focused inward, which will cause excessive use of the medial rectus muscle and cause symptoms of visual fatigue.

2. The vision of a hyperopic eye is determined by the degree of its hyperopic refraction and the strength of its accommodation. Mild hyperopia can be overcome with a small amount of accommodation, and both near and far vision are normal, usually asymptomatic. This type of hyperopia is called latent hyperopia. Slightly more severe hyperopia or insufficient accommodation results in poor near and far vision. The remaining part that cannot be completely compensated by accommodation is called manifest hyperopia. The sum of latent hyperopia and visual acuity is called total hyperopia. Hyperopic eyes are prone to symptoms of visual fatigue due to being in a state of accommodation tension for a long time.

3. Symptoms of visual fatigue refer to blurred handwriting or targets, dry eyes, heavy eyelids, fatigue, eye pain and headache after reading, writing or doing close work for a long time. The symptoms will be significantly reduced or disappear after a short rest. This symptom is most common in the afternoon and evening. In severe cases, it may even cause nausea and vomiting. Sometimes it may be complicated by recurrent chronic conjunctivitis, blepharitis or styes.

4. People with low refractive power may have no symptoms. People with slightly higher astigmatism may have decreased vision, and vision at both near and far is unclear, with double vision and often symptoms of visual fatigue.