It is said that only people with shortsightedness can understand this picture...

Do you remember what steps are usually taken before getting glasses? That's right, it's optometry. During optometry, you will sit in front of a machine, and as the screen changes, the optometrist will ask you a variety of questions and determine your myopia based on these questions.

Optometry source｜pixabay

Do you remember this picture that always appeared in front of your eyes when you had your eyes tested? It showed green farmland and a small red or green house in the distance. What is the purpose of this picture? Why is it so famous in the optometry community? And why was this image chosen?

1. What is “eye examination”?

"Optometry" refers to the test of the concentration of light after entering the eyeball. It is generally used to detect the degree of myopia and is a very common technical operation in optical shops or ophthalmology hospitals. The instrument for optometry is called "full-automatic computer ophthalmometer", which can use circular infrared light to illuminate our eyes and calculate the angle of light rebounding from the bottom of the retina to obtain the specific diopter.

Computer ophthalmometer source | freepik

The computer ophthalmometer has a high degree of automation. It can quickly analyze the measured eye signals through the computer and output the value of human eye refractive error in the form of digital display or print. It is precisely because of the characteristics of automation, rapidity, and accuracy that the instrument has become one of the necessary equipment for eyeglass stores or ophthalmology hospitals to perform eye examinations and glasses.

2. What is the use of the red house in optometry?

If you want to measure more accurate values, optometrists must ensure that our eyes are in a relatively fixed and relaxed state. To achieve this goal, researchers invented the "cloud method".

Cloud and fog method source | Internet

The "cloud method" uses a convex lens to make the eyes lose focus. The individual will feel that everything in front of the eyes is blurry, and only most of the color blocks can be seen clearly, as if there is a layer of fog in front of the eyes. As the convex lens is adjusted, the image in front of the eyes will become clearer and clearer. In this process, your eyes will also be relaxed accordingly. The red house in the distance of the image will attract your sight, thus achieving the effect of fixing your sight.

In addition to the red house, there are many other unique inspection items in optometry. In addition to the familiar E sight mark, there are also C sight marks, red and green sight marks, radial sight marks, honeycomb sight marks, etc. They are all important inspection items in optometry and can provide more scientific data support for fitting glasses.

3. Does the “Red House” really exist?

Why did doctors choose a red house among so many designs? In fact, this red house has a prototype in reality, which is the Vik Church in Iceland.

Vic Church Source｜pixabay

This church is located in Heidlisand, Iceland. It was built in 1903 and is the first church built with cement in Iceland and even in the world. Large patches of lupine grow around the church, making it a popular spot for photographers to take photos and tourists to take photos.

Iceland Vik Church Source｜freepik

The picture in the ophthalmometer comes from this Icelandic church with a red roof. Even in reality, if you look at it from a distance, your eyes will definitely be attracted by its red color, just like in the ophthalmometer.

4. More than 600 million people are myopic. Please be kind to our eyes.

According to a World Health Organization research report, there are as many as 600 million myopic patients in China, and the myopia rate among teenagers is the highest in the world. Other research data shows that the myopia rate among teenagers has exceeded 60%, and in the future, 960 million people will wear glasses and enter the door of myopia.

Glasses source｜pixabay

In 2020, the People's Daily Public Opinion Data Center and the Aier Eye Institute of Central South University jointly released the "2020 China Youth Myopia Prevention and Control Big Data Report". The report pointed out that the average daily eye use time of teenagers is more than 4 hours, more than twice the recommended value (<2 hours). Not only that, the myopia rate among teenagers is increasing year by year, and one in every two people suffers from myopia.

At present, there is no way in the world to fundamentally cure myopia. Whether it is OK glasses, frame glasses, contact lenses or laser surgery, they can only improve vision to a certain extent and require continuous maintenance in the future.

Contact lenses source｜pixabay

Therefore, true myopia is irreversible to a certain extent. Once myopia occurs, it may be a lifelong thing. In life, don't look at electronic products for a long time, do more eye exercises, and choose suitable eye protection products, which can help us maintain healthy vision. Use eyes scientifically and take good care of them, starting from you and me.