Preface:

Many posts complaining about OLED eye strain have seen a saying: "Using OLED screens too much makes your eyes even more astigmatized!" ”

Years ago, I consulted an ophthalmologist about this issue, and they said: astigmatism is congenital; you might just be tired from using your phone too much or your myopia has worsened.

Today, let's briefly talk about some things about eye astigmatism, based on some publicly available information and my own books.

Summary of the article:

1. Astigmatism is generally congenital, meaning the eyeball is not "round" enough.

2. Astigmatism is an eyeball defect caused by inconsistent diopters in both X and Y directions, resulting in inability to clearly image images on the retina.

3. Mild cases are not needed; severe cases require glasses for correction or surgery.

4. Theory onlyPopular scienceThis does not constitute medical advice. If you suspect you have eye problems, consult the ophthalmology department of a hospital.

Main Text:

1. What is astigmatism?

Astigmatism is a manifestation of abnormal refractive light in the eye. (Refractive errors include: myopia, hyperopia, astigmatism)

Several common refractive errors

Under normal circumstances, the surface of the cornea (i.e., the refractive interface of the eyeball) is spherical, like a ball, with the curvature of different cross-sectional surfaces being exactly the same, allowing images to be accurately and clearly projected onto the retina.

Diagram of astigmatism performance

For astigmatism patients, the curvature of the corneal refractive interface is uneven, forming a rugby ball-shape.

The deviation between two arcs causes different refractive powers, causing light entering the eye from various angles to focus not at a single point but multiple points. As a result, the image becomes blurry.

2. Causes and symptoms of astigmatism

Astigmatism is mainly congenital and generally unrelated to prolonged reading or computer use.

The degree of astigmatism is also relatively stable and generally does not worsen with time and age like myopia. However, if astigmatism is caused by certain eye conditions, such as keratoconus, the degree of astigmatism may worsen.

Symptoms of astigmatism mainly include blurred vision, blurring of both near and distant objects, and the light appears to "dissolve" (somewhat similar to the out-of-focus diffuse spot on a DSLR camera). This condition may worsen at night.

Simulated astigmatism gaze with a camera bokeh (for reference only)

Congenital astigmatism

Including corneal astigmatism and lens astigmatism, with corneal astigmatism being the main cause. This is because the cornea is not a perfect sphere; due to eyelid pressure, genetics, and other reasons, the cornea is often not "round" (closer to a rugby ball), which is also the source of astigmatism for most people.

Diagram illustrating the causes of astigmatism

Acquired astigmatism

Conditions like inverted eyelashes, eye rubbing, or improper eye habits can affect corneal morphology (under external pressure), which may increase astigmatism, though the degree is generally not very high.

How should astigmatism be corrected?

Mild astigmatism generally does not cause symptoms and does not require correction. However, if the degree of astigmatism exceeds 100 degrees, correction should be considered, and depending on the degree of astigmatism, glasses or surgery can be chosen. (This is for overview only and does not constitute medical advice!) If needed, you may consult the hospital's ophthalmology department)

A simple self-test for your own reference

Test steps:

(1) Remove your glasses (whether frames or contact lenses);

(2) Hold the phone at eye level, move it horizontally from far to near, and hold the position when the line is just visible;

(3) Gently cover one eye and use one eye to look at the picture below;

(4) Distinguish the color depth of the dashed lines in the picture.

Astigmatism self-measurement chart

Self-test conclusion:

● If all dashed lines are evenly arranged without significant distinctions, there is no obvious astigmatism in the eyes.

● If the dashed line with one eye appears especially clear and bright in one direction, it indicates a certain degree of astigmatism.

Note: The above tests are preliminary evaluations only. If you need to learn more about eye parameters, it is recommended to have a comprehensive medical eye exam at a reputable eye hospital!

Astigmatism is very common, mostly a congenital refractive error, generally stable and not worsening over time.

However, you should still pay attention to eye hygiene in daily life to prevent eye fatigue and worsening myopia!

According to the literature: astigmatism is mostly caused by congenital abnormal corneal development.

Because there may be some controversy, here's the source:

Ye Shunbin, Wang Zhanmin. Common Clinical Issues and Their Management, 4th Edition [M]. Changchun: Jilin Science and Technology Press, 2000:453-457.

Descriptions of astigmatism in professional medical books

It is widely recognized that unscientific (in poor lighting conditions) using OLED screens negatively affects vision, but misinterpreting or misinterpreting some medical concepts is completely unnecessary. I hope this article will clear up some misunderstandings about medical concepts. If there are any mistakes or deviations, please feel free to point them out!

#LCD永不为奴 ##酷安科普 ##呵护眼睛 #

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