What causes presbyopia?


Presbyopia is a vision problem that will inevitably occur after entering middle-aged and elderly people. It is also a physiological phenomenon that naturally occurs with age. People with normal vision usually begin to have presbyopia symptoms about the middle age of 40 ages.

With the increasing amount of eye use and the unscrupulous overdraft of the eye, the age of presbyopia is constantly increasing.

In addition, factors such as our usual eye refractive status, reading habits, physical fitness, and living environment will affect the time and severity of presbyopia.

For "presbyopia", you should at least know these.

First of all, let's popularize the term "presbyopia".

What is presbyopia?

Presbyopia refers to people who are getting older and have difficulty in reading or working at close range. This is a phenomenon of human body function aging. It is caused by the natural decline of the body's accommodative power during aging. The vision cannot be fully adjusted to the required vision when need close reading, and only part of the adjustment can be replaced with the help of lenses.

Let's first look at the symptoms associated with presbyopia:

1. Difficulty seeing close places

It is difficult to see close objects clearly, which is academically called "difficulty seeing near." People with presbyopia will gradually find that when reading at the working distance they are accustomed to, they will not be able to see the smaller words. They need to tilt their heads back or take the books and newspapers farther to see the words clearly, and the reading required The distance increases with age.

2. Need stronger lighting when reading

On the one hand, sufficient light increases the contrast between the book and the text; on the other hand, when the light increases, the pupils automatically shrink, the depth of field increases, and vision improves.

3. Difficulty to look at close objects for a long time

Due to the decreased accommodative ability of the eyes, presbyopia needs to keep the eyes at the accommodative limit when working at close range, so it cannot last. Some people with presbyopia may experience asthenopia symptoms.

Therefore, we must learn more about the vision correction of presbyopia.

The difference between reading glasses and hyperopia lenses

Reading glasses ≠ hyperopia lenses

On the surface, presbyopia is the same as hyperopia. It is difficult to see near things and needs to be corrected by wearing a convex lens. But there are essential differences between hyperopia vs presbyopia. Presbyopia is a natural phenomenon of human aging, while hyperopia is a refractive error and a pathological phenomenon.

Presbyopia can’t see near clearly, but it’s normal to see far. Wearing reading glasses is mainly to correct near vision. There is no need to wear reading glasses when you see far; farsighted eyes have defects in near and far vision, and mild farsightedness can be adjusted by the ciliary muscle. Even if you don't wear reading glasses, it is normal to see near and far, but severe hyperopia is beyond the adjustment ability of the eyes. It is necessary to wear eyeglasses to correct near and far vision at the same time.

In a word, farsightedness and presbyopia are not the same things.

Therefore, when the elderly find that they are not able to see close, they should not go to the street to buy a pair of reading glasses but should consult an ophthalmologist as soon as possible to confirm the reason. If it is hyperopia, you should determine whether you need glasses correction according to the severity. Generally speaking, it is best to use glasses for high hyperopia of 500 degrees and above. If it is presbyopia, you also need to check the optometry to determine the degree and then wear a pair of reading glasses that suits you.

Ready reading glasses are not suitable for all presbyopic people

The presbyopic lenses sold on the market are generally 50° presbyopic lenses, with a fixed interpupillary distance and the same power for both eyes.

Because the wearing time is not long and the accuracy requirements are not high, to greatly reduce the manufacturing cost and simplify the product, the merchants all make the eyes power consistent, and the interpupillary distance is also uniformly produced with a fixed value. The lens is generally selected at a lower price. Of acrylic lenses.

The degree generally has several degrees such as +1.00, +1.50, +2.00, +2.50, +3.00, +3.50, +4.00.

However, ready reading glasses are not suitable for the following people:

A. People whose eyes have a power difference of more than +0.50.

B. People with the big difference between pupil distance and lens size.

C. People with large differences in the size of the pupil distance between the left and right eyes.

D. People with sensitive eyes.

E. People who wear reading glasses for a long time.

F. People with presbyopia after myopia.

Finally, let's take a look at how to prevent presbyopia from occurring in advance (but not avoidable):

1. Pay attention to rest, live regularly, and ensure adequate sleep and not stay up late.

2. Avoid using your eyes for a long time, and reduce the time to read books or electronic screens at close range.

3. When using your eyes too much, pay attention to close your eyes to rest or look far away. You can use a warm towel to cover your eyes and do eye exercises frequently to relieve eye fatigue.

4. When doing outdoor activities or staying in the sun for a long time, wear sunglasses with anti-ultraviolet radiation function.

5. Eat carrots, blueberries, black sesame seeds, and other foods that contain more antioxidants, vitamin A, and β-carotene.

6. Check eyesight regularly that ensure your eyes will not get occur presbyopia.