Eating pork liver to prevent and treat nearsightedness is a well-known "food therapy secret," but Wang Yusheng, director of the Ophthalmology Department at Xijing Hospital of the Fourth Military Medical University, states that this is actually a misconception.
It is widely believed that pork liver is very high in vitamin A, and vitamin A is indeed good for vision, but its main effect is on the eye's ability to see in low light, i.e., its adaptation to dim light.
A lack of vitamin A can lead to a reduced ability to adapt in low light (taking a long time to see after moving from a bright place to a dim one, or a long period from not being able to see to gradually being able to see). In severe cases, it can cause night blindness and damage to the eye's conjunctiva or cornea.
We know that many foods are rich in vitamin A, and this is not exclusive to pork liver. Vegetables, fruits, and other meats also contain it, such as carrots, pumpkins, and pork, which also have relatively high levels.
Director Wang Yusheng said that some people with nearsightedness believe that eating pork liver can improve their vision. In fact, the cause of nearsightedness is due to the deformation of the eyeball—the increase in its axial length—which prevents the lens from focusing properly on the retina. No matter what food you eat, or even medication, it is impossible to change the shape of the eyeball and restore its normal axial length. How could it possibly help treat nearsightedness?
Director Wang pointed out that to prevent nearsightedness, one should first maintain good eye hygiene and ensure a balanced diet. It is also possible to eat more foods rich in vitamins and trace elements. Of course, patients with myopia should still seek regular treatment from a specialized hospital, as there is no particularly effective dietary therapy method.