What causes eye flashes?

Wet eyes, dry eyes, sparkling eyes. Various eye symptoms. Eye flashes are an abnormal refractive condition of the eye and are related to the curvature of the cornea. Human eyes are not perfect. Some people's corneas are curved in some angle areas and flatter in other angle areas. The reasons for eye flashes are introduced in detail below. You can follow the editor to learn more.

The reason for the flash is that the uneven thickness or curvature of the cornea makes the refractive rates of the various meridians of the cornea inconsistent, so that the light passing through these meridians cannot be focused on the same focus. In this way, the light cannot be accurately focused on the retina to form a clear image of the object. This situation is called astigmatism.

Types of regular flashes Most flashes are caused by congenital abnormalities of the cornea, and lens flashes may also exist. There are also some acquired causes of flashes, such as styes or milia on the eyelids, and long-term poor eye posture (such as frequent squinting, rubbing eyes, reading while lying down, etc.). The pressure of the eyelids on the cornea can also change the curvature of the cornea, causing astigmatism and increasing the degree of astigmatism. In addition, some eye surgeries (such as cataract and corneal surgery) may also change the degree and axis of astigmatism.

Irregular astigmatism is mainly caused by the unevenness of the corneal refractive surface, such as corneal ulcers, scars, keratoconus, pterygium, etc. What causes eye flashes? Why do eye flashes occur? There are many reasons for flashes, the most important of which is caused by changes in the curvature of the cornea of the eye. The cornea, also called the "black pupil", is a window in front of the eyeball. It is not only smooth and transparent, but also in a complete hemispherical shape. Its main function is to collect light through the pupil and focus it on the retina at the bottom of the eye, which is then reflected to the brain.

Can see the outside world clearly. Therefore, when the curvature of the hemispherical cornea changes, like an unevenly polished lens, and the surface becomes uneven and irregular, the external light cannot form a focus on the retina, but diffuses in all directions, making the brain's perception of external objects blurred, thus producing astigmatism. This type of astigmatism is medically called irregular astigmatism. Because the curvature of the cornea changes so much, it is difficult to correct with glasses.

There is also a type of astigmatism called regular astigmatism, which is caused when the curvature of the cornea in a certain direction is inconsistent with its vertical direction. There are many types of astigmatism, including simple hyperopic astigmatism, simple myopic astigmatism, compound hyperopic astigmatism, compound myopic astigmatism and mixed astigmatism, etc. Most of them are caused by different refractive powers of the cornea and exist at the same time as myopia or hyperopia. They can be corrected with glasses. There are two reasons for irregular flashes caused by uneven cornea and incorrect curvature: one is congenital and inherited, and the other is due to acquired corneal disease. If the cornea is ulcerated or injured, scars will form after healing, which will cause the cornea to be uneven and have an irregular curvature.

Regular mild astigmatism generally does not affect vision, but may cause discomfort such as eye fatigue. Many people will experience headaches, soreness in the eyes and around the eye sockets and other discomforts when using their eyes for a long time. A few people even have symptoms of nausea and vomiting, which has a certain impact on their health and work. When the astigmatism is more serious, objects appear blurry, which has a greater impact on work.

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