What are the common problems in optometry and glasses fitting?

Some parents who have myopic children think that once their children put on glasses, they can't take them off. Is this really the case? Tang Yan, director of the optometry department of Beijing Aier Yingzhi Eye Hospital, said: After a child develops true myopia, choosing a regular hospital for optometry and glasses fitting is to allow the child to see more clearly and reduce visual fatigue. The so-called decreased vision and increased degree after wearing glasses are not caused by the glasses.

When it comes to optometry and glasses fitting, what other questions often bother myopic patients and their parents? Today, Director Tang Yan will answer your questions.

QWill wearing glasses cause my degree of myopia to increase?

A: No.

The increase of myopia in children is caused by many factors, such as long-term close-up use of eyes, bad eye habits, incorrect reading and writing posture, insufficient outdoor time, etc., which will make myopia increase. In addition, myopia is also affected by genetic factors, environmental factors, etc. If the glasses currently worn are not suitable or the pupil distance is not correct, wearing such glasses for a long time may also lead to the increase of myopia.

Director Tang Yan said that the developmental factors of children and adolescents also affect the progression of myopia. As they are in the growth and development stage, the eye axis will lengthen as the body develops. "If the eye axis grows by 0.1mm, myopia will generally increase by about 25 degrees."

QIs it better if the frame is lighter?

A: No.

The function of the eyeglass frame is first to fix the lens and ensure that the lens is in the correct position, so that the wearer can see through the optical center of the lens to obtain clear and comfortable visual effects; secondly, to ensure wearing comfort and stability. The right frame will fit the face, and its nose pads and temples can be adjusted according to the shape of the individual's nose bridge and ears, so that the glasses can be worn firmly on the face and reduce the pressure on the face; finally, it has an aesthetic effect. The styles and colors of the frames are diverse, which can reflect personal style and is a fashion accessory.

Director Tang Yan reminded that the lighter the frame, the better, and the weight of the frame is not the only criterion. Light frames can reduce the pressure on the bridge of the nose and ears, but frames that are too light may cause instability and slippage, affecting visual effects.

For those who do a lot of exercise or need to put on and take off their glasses frequently, easily deformed frames will affect the optical correction effect of the glasses. In addition, frames that are too light may also be limited in style. Therefore, it is necessary to comprehensively consider the weight, material, stability, style and personal needs of the frame to choose the right frame.

QAre thinner lenses better?

A: No.

Director Tang Yan introduced: Although thin and light lenses may look more beautiful and put less pressure on the bridge of the nose, the thickness of the lens is related to the refractive index of the lens, and high-refractive-index lenses often sacrifice a larger Abbe number, thus affecting the clarity of the image and the authenticity of the color.

Relationship between refractive index and Abbe number

The higher the refractive index of the lens, the thinner the lens, but the lower the Abbe number, the more obvious the dispersion phenomenon. Lenses with low Abbe numbers will cause the image of objects on the retina to be less realistic, which may affect the visual experience.

Director Tang Yan mentioned: The thickness of the lens not only affects the appearance and weight, but more importantly, it affects the visual effect and the safety of the user. Thinner lenses may be more likely to break, especially at high temperatures or under external impact, which may pose a threat to the safety of the eyes.

In addition, high refractive index lenses are usually more expensive because they require more advanced technology and materials to achieve. When choosing lenses, you should consider your personal vision needs, your requirements for visual effects, your budget, and your personal preferences. You don't have to choose the thinnest lenses, but you should choose the lenses that best suit you, which can meet your vision needs while ensuring visual quality and safety. It is recommended to consult a professional ophthalmologist to get the most suitable lens recommendation for you.

Director Tang Yan reminds myopic patients and their parents that they should choose a regular ophthalmology hospital for professional medical optometry when getting glasses. A pair of glasses with appropriate degrees and accurate parameters can help patients reduce visual fatigue when using their eyes at close range, thereby protecting our eyesight. Don't just pursue lightness, thinness, and beauty!