Why Should I Get My Eyes Checked Regularly?
How often should I get my eyes check? The importance of an annual eye exam is not only to ensure that your vision is not blurred, but also to protect the health of your eyes. The visual performance of the human eye includes: light perception, color vision, form sense (sight), kinesthesia (stereoscopic vision) and contrast (contrast sensitivity). The examination of visual function relies on the visual testing chart, color vision examination plates, visual perimeter, dark-adaptometer, and other instruments to check the above-mentioned functions of the eyes. The visual function examination we usually discuss actually refers to binocular vision.
What is binocular vision?
The images formed by external objects in the corresponding parts of the retina of the two eyes are merged into one through the visual center of the brain, making people feel that they are not two separate objects, but a complete three-dimensional image. This function is called binocular vision. This is the foundation for our eyes to see the world.
The binocular vision function can be divided into three levels, simultaneous vision, binocular fusion, and stereoscopic vision. Simultaneous vision means that both eyes have the ability to look at and perceive at the same time. Binocular fusion is based on the normal simultaneous perception of both eyes. Through the analysis and processing of the brain, two images with slight differences in the corresponding points of the retina of both eyes can be integrated into a complete object image. Stereoscopic vision is the perception that the two eyes can distinguish the shape of the object from the perspective of the object. The object is three-dimensional, not just flat like a photo.
By checking the movement function of the eyeball (collection ability), the adjustment ability of the eyes, and whether the collection and adjustment match, it can be judged whether the binocular vision function is normal. Only with normal visual function can we see things clearly, comfortably, and lastingly. There are no obvious symptoms in the initial stage of visual function abnormal. When it develops to a certain degree, visual fatigue will appear.
The relationship between these three levels of visual functions?
After birth, what a person's eyes see is not necessarily the real world. Only two weeks after birth, what the child sees gradually corresponds to the physical objects in the outside world. At 17 months, some children have been able to achieve planar vision close to adults, with first-level vision function. When the first-level visual function is perfect, the second-level visual function has a chance to be established. However, some children cannot achieve this vision for various reasons. At this time, the formation of secondary vision function will be affected.
In order to see things clearly, the eyes must be able to stare at an object in order to form two flat images that can be merged. The eyeball must have the ability to accurately track targets at different distances. From near to far, the position of the eyeball is different. Only when the range of eye movement required to track near and far targets can be achieved, accurate tracking be ensured. This range is called the fusion range. The normal fusion range is from -5° to +25°. But if this range is less than 10°, even the originally formed secondary visual function may be lost. Not only will the secondary vision function be lost, but there may also be squint. Without binocular fusion, the secondary visual function, there will be no conditions for achieving tertiary visual function. Therefore, in the stage of children's vision development, it is very necessary to check the vision and binocular vision regularly!
Importance of binocular visual function examination
The result of optometry is the refractive state of the eye at that time, which can generally meet the optometric distance to see clearly. In normal life and work, we need to see objects at different distances, which requires the participation of binocular vision. Therefore, a examination of binocular visual function should be performed after the refractive examination. If you find that binocular visual function is impaired, you can develop a corresponding visual function training program. Use tools to exercise the eye vision system to improve visual function and visual comfort. Even with the same diopter, different conditions of binocular vision function require different correction methods.
Many adolescents with visual fatigue and rapid growth of myopia will have binocular visual function abnormalities such as accommodation and aggregation. Through binocular visual function examination and corresponding training, visual function can be effectively restored and visual fatigue can be relieved. Studies have shown that this may also be helpful for myopia control.
For adolescents and children with myopia, after a comprehensive binocular visual function examination, they can choose a variety of different correction options, including spherical lenses, aspheric lenses, anti-fatigue lenses, progressive lenses, orthokeratology lenses, binocular visual function training, etc., to solve the problems of rapid deepening of myopia and diplopia caused by abnormal binocular vision.
For adults, based on the results of the examination, reasonable correction, reasonable wearing of glasses, and reasonable training can effectively solve the problems of asthenopia, eyestrain, eye swelling, near-sight difficulties, drowsiness, etc. caused by abnormal binocular vision. Only with normal binocular vision can you enjoy comfortable and long-lasting vision.