What are the differences between presbyopia and cataracts?

Many people think that "poor eyesight as one gets older" is one thing, but in fact, presbyopia and cataracts are two different "aging phenomena", just like hair turning white and teeth loosening, each having its own origin.
Presbyopia: The "focusing device" in the eyes has malfunctioned
In our eyes, there is a structure similar to a camera lens called the lens. When we are young, it is soft and elastic, enabling us to quickly focus both far and near. But after the age of 40, the lens gradually hardens and loses its elasticity, just like an aged rubber band that can no longer be stretched - this is presbyopia.
Data shows that presbyopia usually occurs around the age of 38, with a peak between the ages of 42 and 44. The incidence rate of presbyopia among people over 52 is close to 100%[1]. Presbyopia is as common as white hair.
Presbyopia is a physiological phenomenon rather than a disease. Just like people always develop wrinkles, it does not affect vision health; it merely requires a pair of "reading glasses" to assist.
Cataract: The "lens" in the eye becomes cloudy
If we compare the eyes to a camera, presbyopia is a problem with the focusing function, while cataracts are due to the lens itself becoming cloudy. A normal lens is clear and transparent, just like clean glass. When cataracts occur, the lens becomes cloudy, and seeing things is like looking through a layer of frosted glass.
The development of cataracts occurs quietly: at first, one may just feel that things are a bit "foggy", and when taking a walk at night, the headlights of oncoming cars appear like a blurry ball of light. Later, gradually, I couldn't even see the words on the magnet on the refrigerator or the dates on the calendar clearly. According to statistics from the Ophthalmology Branch of the Chinese Medical Association, the incidence rate of cataracts among people over 60 years old in China is approximately 80%.
Unlike presbyopia, cataract is a disease that can lead to blindness in severe cases. However, it can be treated by replacing the cloudy lens through surgery, allowing the eyes to regain their sight.
What should I do if I get presbyopia and cataracts?
Nowadays, cataract surgery is no longer simply about "changing to a transparent lens". The doctor makes a tiny incision of 1.8 to 3 millimeters to break and remove the cloudy lens, and then implants a functional artificial lens - this is not an ordinary "lens", but an "intelligent lens" that can simultaneously solve myopia, presbyopia and cataracts.
This kind of functional intraocular lens (multifocal, continuous range, trifocal, etc.) is like the zoom lens of a camera, capable of automatically focusing on different distances such as far, medium and near. Looking at the bus license plate in the distance, the instructions on the medicine box nearby, and the TV screen in the middle, all can be switched freely, which is equivalent to completing "cataract treatment + presbyopia correction" in one operation.
Misconceptions about presbyopia and cataracts
Misconception 1: "Presbyopia doesn't need to be treated; just wear a pair of glasses."
Indeed, presbyopia requires wearing reading glasses, but the way of choosing glasses is very crucial. Many mothers, for convenience, spend several dozen yuan at the entrance of the vegetable market to buy a pair of reading glasses, but they still feel dizzy when looking at things.
The correct approach is to have your eyes examined at a professional ophthalmic medical institution and get a pair of reading glasses tailored to your prescription. If you have both myopia and astigmatism, you also need to customize progressive multifocal lenses. In addition, the degree of presbyopia changes with age. Generally, it is necessary to have an eye examination and get glasses fitted again every three years.
Misconception 2: "Cataracts can only be operated on when they are fully ripe."
In the past, medical technology was limited, and cataract surgery could only be performed when it was "mature". However, nowadays, phacoemulsification surgery technology and femtosecond cataract surgery technology have become very mature. As long as vision decline affects normal life (such as being unable to see the road clearly and easily falling, or being unable to distinguish seasonings when cooking), surgery can be performed.
Overripe cataracts can increase the difficulty and risk of surgery. Currently, in clinical practice, it is recommended that when the corrected vision is lower than 0.5, surgery can be considered.
Misconception 3: "Eye drops can cure cataracts
At present, no eye drops can reverse cataracts. The principle of cataract is the turbidity caused by the denaturation of lens proteins. Eye drops cannot reverse the already denatured proteins. Those eye drops that claim to "eliminate obstacles" can at most temporarily relieve dry eyes and have no effect on the cloudy lens.
Rather than spending money on eye drops in vain, it is better to have regular check-ups and have the surgery in time when necessary - this is the current scientific way to treat cataracts.