What Is Presbycusis?

Presbyopia, or presbyopia, is a physiological phenomenon. It is not a pathological state or a refractive error. It is a visual problem that must occur when people enter middle-aged and elderly. It is one of the signs that the body is starting to age. With age, the lens of the eyeball gradually hardens and thickens, and the adjustment ability of the eye muscles also decreases, resulting in a reduction in zoom ability. Therefore, when looking at a close object, because the image cannot be fully focused when projected on the retina, looking at a close object becomes blurred. The occurrence and development of presbyopia are directly related to age. Most of them occur after the age of 45. The occurrence and severity of presbyopia are also related to other factors, such as the original refractive error, height, reading habits, lighting, and general health. . Even if you pay attention to protecting your eyes, the degree of eye presbyopia will increase with age, and it generally increases at a rate of 50 degrees every 5 years. According to the correspondence table of age and eye presbyopia, most of the eyes have a good refractive condition, that is, people without myopia and hyperopia. At 45 years old, the eye presbyopia is usually 100 degrees, and at 55 years old, it is increased to 200 degrees. Around the age, the degree will increase to 250 degrees to 300 degrees, after which the degree of eye presbyopia generally does not deepen.

Basic Information

English name: presbyopia
Visiting department: Ophthalmology

Multiple groups: 45 and over
Common causes: Diminished eye accommodation
Common symptoms: Blurred reading at close range

Causes of presbyopia

The essence of presbyopia is the decrease in the ability of the eye to adjust, and age is a major factor affecting the ability to adjust. The adjustment, that is, the increase in the eye's refractive power, is achieved by the shaping and convexity of the lens. The crystals continue to grow throughout life, because epithelial cells in the equatorial region continue to form new fibers, new cortex is constantly added to the sides of the crystal, and old fibers are squeezed toward the nuclear area. As the age increases, the crystal density gradually increases and the elasticity gradually decreases. In addition to age, the occurrence and development of presbyopia are also related to the following factors:

Refractive error

Farsighted eyes appear presbyopia sooner than nearsighted eyes. After wearing myopic glasses, myopic eyes have a correction distance of 12 to 15mm from the corneal apex, reducing the need for adjustment of the same reading distance. Myopia wearing contact lenses Because the contact lens is worn on the corneal surface and its corrected optical system is close to the emmetropic eye, it is premature to wear a contact lens before a person wearing ordinary frame glasses.

2. Eye method

The need for regulation is directly related to the working distance. Therefore, presbyopia is prone to occur in close-range fine workers. People who work in fine close-range work have presbyopia earlier than those who work in long-distance work.

3. Physical fitness of the patient

The taller man with long arms has a longer working distance than the shorter man with shorter arms, requiring less adjustment, so the latter has presbyopia symptoms earlier.

4. Geographical location of the patient

Because of the effect of temperature on the crystal, people living near the equator appear presbyopia earlier.

5. The effect of drugs on patients

Patients who take insulin anxiolytics, antidepressants, antipsychotics, antihistamines, anticonvulsants, and diuretics will see presbyopia earlier due to the effect of the drug on the ciliary muscle.

Clinical manifestations of presbyopia

The discomfort of presbyopia varies from person to person, because it is related to factors such as personal refractive status, eye habits, occupation and hobbies. For example, the subjective perception of presbyopia by a close-up fine worker is much stronger than that of a traffic policeman whose main task is to watch distant vehicles and traffic lights.

Difficulty viewing

Patients will gradually find that they can't read small fonts at normal working distances, and see relatively far away. Patients can unconsciously tilt their heads back or take books and newspapers farther away to see the words clearly, and the reading distance required increases with age.

2. Reading requires more illumination

At first, reading at night was a bit uncomfortable because the lights were dim at night. Insufficient lighting not only increases the visual resolution threshold, but also dilated pupils. Due to the dilated pupils, a large diffuse circle is formed on the retina, which makes the symptoms of presbyopia more obvious. With the increase of age, even near-distance work during the day is prone to fatigue, so presbyopic people prefer to use brighter lights when reading at night. Sometimes the light is placed between the book and the eyes. This will not only increase the contrast between the book and the text, but also reduce the pupil. However, the light in front of the eyes will inevitably cause glare interference. The closer the interference light source is to the visual axis, the greater the impact on vision. Some elderly people like to read in the sun. This is the reason. Indoor light, the elderly can improve the brightness to improve vision. For reading materials, the elderly have high requirements for bright contrast, so they should provide reading materials with clear printing, large fonts, and clear black and white. Avoid using blue, green, and purple backgrounds.

3. Nearsightedness cannot last

Insufficient adjustment means that the near point gradually becomes farther away, and the nearby objects can be clearly seen after hard work. If this effort exceeds the limit to cause tension in the ciliary body, when looking at distant objects again, the tension in the ciliary body cannot be relaxed immediately, so temporary myopia is formed. When you look at nearby objects again, there is a short period of blurring, which is the performance of slow response. Fatigue occurs when the ciliary muscles are approaching their functional limits and are unable to keep working. Because the accommodation force is diminished, the patient must work close to the limit of the binocular adjustment, so it cannot be sustained. At the same time, due to the linkage effect of the adjustment set, over-adjustment will cause excessive collection, which is also a factor that causes discomfort. Therefore, the serialized handwriting of the newspaper is doubled, and finally it cannot be read. In some patients, symptoms of eye fatigue such as eye swelling, tearing headaches, and itchy eyes may occur. Due to the sluggish response of the adjustment, you can see the near objects clearly after working hard. When you look at the distant objects again, due to the tension of the ciliary body, you can't relax immediately, so temporary myopia is formed. When you look at nearby objects again, there is a short-term blur, that is, the performance of slow response is adjusted, and if you continue to develop, you will have sour eyes, eye pain, eyelid twitches, dry eyes, photophobia, tears, headache, dizziness, nausea, A series of symptoms of visual fatigue such as irritability, presbyopia is the main cause of visual fatigue in middle-aged and elderly people.

Presbyopia examination

For any presbyopic, the first step in optometry is the detection of long-distance ametropia, that is, the standard basis of accurate optometry procedures for accurate ametropia and refraction is the beginning of successful presbyopia. The fitting physician must establish this concept and be proficient in standardized optometry procedures.

Accurate optometry and fully correct myopia, hyperopia and astigmatism. Near-additional measurements should be performed with the standard working distance selected under the condition of complete refractive correction, with both eyes looking at the same time. Select the appropriate visual target (reading material) and appropriate lighting system during the test. When the prescription is finalized, reasonable adjustments should be made according to individual needs.

Presbyopia diagnosis

The diagnosis can be made based on the results of hyperopia in combination with the patient's age and clinical manifestations.

Presbyopia Treatment

Optometry is a reliable and effective method. After excluding the factors of nearsightedness and farsightedness, the principle of being able to see near objects clearly without discomfort should be matched with suitable glasses. Presbyopic power is usually + 1.00D for presbyopic eyes around 40 years old, and it will be increased by + 0.5D-+ 1.00D for each additional 5 years old; if the original refractive error, the optical power should be the original refractive error plus presbyopia degree. If the reading power of presbyopia increases quickly, and it is difficult to obtain satisfactory results when changing glasses frequently, cataracts and diabetes in the eyes should be ruled out in time.

Convex lens correction

The principle of convex lenses to correct presbyopia: compensate for the lack of accommodative lens power to achieve the purpose of correcting presbyopia. This includes the traditional single-light (single-focus) lens and the double-light (dual-focus), progressive multi-focus lens that has appeared in recent years .

(1) Single-lens mirror The single-lens mirror is the simplest and most popular method among all correction methods, and it is only suitable for near use.

(2) Double mirror Double mirror can provide patients with far and near vision at the same time, but if it appears during use. In the case of undercorrection of hyperopia or overcorrection of nearsightedness, intermediate vision blurring occurs after the optician, which makes it difficult for patients to obtain the desired visual quality.

(3) Gradient multifocal lens Gradient multifocal lens is to see near, middle and long distance objects through different areas on the same lens. It solves the problem of blurred vision in the middle caused by two-lens mirror. So far the ideal method to correct presbyopia. While ensuring clear and near vision, it also guarantees good middle and long distance vision. However, there is a certain distance between the lenses of the spectacles and the apex of the cornea, which results in a certain degree of magnification of the height-number lenses, which easily causes the wearer to have a certain degree of discomfort and dizziness. The liquid crystal diffractive mirror that is still under study hopes to solve these problems.

2. Food therapy

Can be used as a supplementary measure. Chrysanthemum medlar tea prevents presbyopia, 5 grams each of white chrysanthemum and medlar, brew with boiling water, substitute tea, 1 dose daily, and take it for 3 months. It has the effect of nourishing liver and kidney and clearing liver. Especially suitable for presbyopia and unclear vision.

Regarding the law of human aging, Chinese medicine has known about it more than 2,000 years ago. Presbyopia is mainly due to the natural aging of the spleen, stomach, liver, and kidneys. Lycium barbarum is an essential medicine for nourishing the liver and kidneys, and it can also clear the eyes; chrysanthemum can clear the liver and eyesight, and the two cooperate with each other to clear up and replenish the specimen, taking into account the specimen, which has obvious protective effects on the eyes.

Presbyopia Prevention and Care

Eye wash in cold water

Wash your eyes and face with cold water every morning and before going to bed. Soak your eyes in clean cold water for 1 to 2 minutes or pour water into your eyes with hands, then dry the eyes with a towel, then gently rub around the eyes with your fingers about 30 times.

2. Timely overlook

Get up early, noon, and before dusk every day, and look 1 or 2 times in the distance. Choose the furthest target, and keep your eyes on the object for about 10 minutes.

3. Blink often

Blinking often can stimulate and enhance the kinetic energy of the eye muscles and delay aging. The practice is to open and close blinks, about 15 times each time, while rubbing the eyes with both hands to moisturize the eyes.

4. Rotate the eyeball

Clockwise and counterclockwise rotation can improve eye muscle blood circulation and refreshing.

5. Hot eye protection

Use a hot towel on your eyes and exchange them several times to make the blood vessels in the eye flow smoothly and provide oxygen and nutrients to the eye muscles.

6. Prevent eye fatigue

When reading newspapers and TV, keep a certain distance, not too long, to prevent eye muscle and vision fatigue.