Defending Health: Start with Preventing Poor Posture
The so-called "sub-health" we often talk about is often overlooked because its symptoms are not too obvious and do not immediately affect daily life and work. Therefore, the symptoms of sub-health are repeatedly ignored and fail to attract people's attention. For the sake of your physical health, it is especially important to prevent sub-health and keep its symptoms away.
Poor posture not only leads to a hunched back, affecting appearance, but also causes uneven stress on the spinal joints, leading to neck, shoulder, waist, and back pain. Therefore, people should take measures to prevent a hunched back. The primary countermeasure is to correct poor posture in daily life and work. This means maintaining a correct posture; when working at a desk, the height of the table and chair should be appropriate. It is essential to keep an upright sitting posture and avoid flexion of the neck, chest, and waist.
However, to clearly see books or other objects on the table or in the front and lower position, people have to lower their heads, placing the cervical spine in a flexed position. This increases the burden on the cervical spine. Over time, it can easily lead to a hunched back or cervical strain, and subsequently, cervical spondylosis. Even some people with regular glasses, to achieve the best viewing angle when reading and writing, hold the book too close to their eyes. At this point, the lenses are almost parallel to the book, placing the cervical spine in an extremely flexed position, which further aggravates cervical strain.
To maintain an upright sitting posture and the natural lordosis of the cervical spine, the angle between the lens and the temple should be 50 degrees, and the angle between the lens and the cheek should be 70 degrees. The lower edge of the lens should be as close to the cheek as possible to allow the line of sight to form a right angle with the lens for convenient reading. Some people, in order to see objects in the front and lower position clearly, often pull their glasses down to the lower part of their nose or the tip of their nose to adjust the optimal viewing angle.
However, the lower part of the nose has no nasal bone, only cartilage. This not only feels uncomfortable but also compresses the nasal wings, affecting smooth breathing. When performing different activities, the angle between the lens and the temple should be different. For these reasons, the angle between a person's glasses and the temple should be designed to be adjustable for elevation and depression.