If you start wearing soft contact lenses at the age of 20, 10 years later, the corneal endothelial cell density will be equivalent to that of a 60-year-old, and you will not be able to withstand any eye surgery. The truth is that contact lenses have an effect on the cornea, but not on surgery. Contact lenses are called “corneal contact lenses” and there are more than one type of contact lenses. RGP is more oxygen permeable than regular soft lenses and has a lower complication rate than regular soft lenses, so it is now getting more attention. Contact lenses do affect the endothelial cells of the cornea. A Japanese study of 126 cases of soft contact lens wearers found that for the same age group, contact lens wearers did have a lower density of corneal endothelial cells than those who did not wear contact lenses. This effect may be caused by the contact lenses blocking the exchange of substances between the corneal endothelium and the outside world. We know that there are no blood vessels in the cornea and that the nutrients and oxygen needed by the cells, as well as the waste products produced by metabolism, are exchanged through the atrial fluid on the inner surface of the cornea and the tear fluid on the outside. Wearing contact lenses prevents this exchange from taking place efficiently, and the cells may be damaged by lack of oxygen. At the same time, the carbon dioxide produced by endothelial cell metabolism cannot be eliminated in time and is retained, which may have toxic effects on the cells. However, the reduction in corneal endothelial cell density is significantly less in people who wear high oxygen permeability rigid contact lenses (RGP) than in those who wear soft lenses. The study also found that the shorter the duration of daily contact lens use, the less likely it was that corneal endothelial cell damage would occur. None of those with less than 12 hours of daily use had a corneal endothelial cell density of less than 2,000 cells per square millimeter. The corneal endothelial cell layer is non-renewable, and various ophthalmic procedures always damage a portion of the corneal endothelium. Among the various ophthalmic surgeries, the most common and significant decrease in corneal endothelial cell count is caused by anterior chamber IOL implantation in cataract surgery, with a loss rate of 7.2% to 17.6%. The Japanese study mentioned earlier showed that the average corneal endothelial cell density was 2610 cells per square millimeter in people who had worn soft contact lenses for more than 20 years. If 20% of the endothelial cells are lost after anterior chamber IOL implantation, the average density of remaining endothelial cells is still 2088 per square millimeter, which is still well above the threshold of 800 per square millimeter. Not to mention that most laser myopia procedures do not damage that many corneal endothelial cells. Therefore, “after 10 years of wearing soft contact lenses, the corneal endothelial cell density will not be able to withstand any eye surgery” is somewhat alarming. Conclusion] Contact lenses may cause a decrease in corneal endothelial cells, and there is a possibility of corneal infections and ulcers and other complications. If you have to wear contact lenses, it is best to wear high oxygen permeable hard lenses if you can. In addition, we should pay attention to proper fitting, short wearing, alternating with frame glasses, and regular eye examinations to protect our cornea from damage.