A picture to teach you how to read diopter

We often say how many degrees myopia is and how many degrees hyperopia is. We have also introduced how to read the eye test form before. This article uses a picture to tell you how doctors record the refractive power. As usual, Jingcai Doctor promises that this is pure popular science, no deception, no selling, please feel free to read:

The picture above is a number axis, with 0 in the middle, negative numbers - on the left, and positive numbers + on the right.

According to the international standards and practices of optometry, the unit of refraction is recorded as "D", which is what we often call "degrees".

Myopia is recorded as "-xxxD", for example, myopia of 300 degrees is recorded as "-3.00D". Yes, if you move the decimal point two places to the right, the number on the optometry report is the degree you usually say.

Similarly, hyperopia is recorded as "+xxxD", for example, hyperopia of 500 degrees is recorded as "+5.00D".

So the question is, 1000 degrees of myopia is definitely more serious than 100 degrees of myopia, right? So is 1000 degrees of myopia more serious or 100 degrees of myopia more serious? Because they are both negative values, according to international standards, -10.00D < -1.00D. Similarly, myopia over 300 degrees should be recorded as "<-3.00D". However, many popular science books and articles may make mistakes in this regard. Just be clear about what is going on.

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About Dr. Jingcai: The creators of Dr. Jingcai's popular science content all have a professional background in ophthalmology, a master's degree or above, and are former ophthalmologists. For some popular science content with a higher degree of professionalism, we will also invite working ophthalmologists and optometry experts to review and check it, striving to be responsible for the accuracy of the content and avoid misleading readers.