Hello: Astigmatism is caused by the uneven thickness of the cornea in the most common and understandable terms. The light passes through the thick part of the cornea to form a clear image in the retina, while the light passes through the thin part to form a blurred image in the retina. The main symptoms are ghosting or deformation of the object. Then more than 70% astigmatism is congenital.

As you said above, you started wearing nearsighted glasses after primary school, but there was no astigmatism. So, was the first optometry in the hospital or in the optical shop? If the light was tested in the optical shop, there may be some errors. Teenagers are advised to go to the hospital for medical optometry for the first time.

If there is no astigmatism before, there are generally two causes: 1. Astigmatism caused by trauma (for example, the cornea is scratched or injured by blunt instruments during exercise). 2. Poor eye hygiene. "I usually like to rub my eyes with my hands, which leads to corneal infection and some damage to the cornea", which leads to the emergence of astigmatism.

As for the operation problem you mentioned, as I said earlier, astigmatism is caused by the uneven thickness of cornea, so now laser surgery uses computer to accurately calculate and thin your cornea evenly to correct myopia. That is to say, after thinning, the thick part of the cornea is still thick, and the thin part is still thin, so it can only correct myopia, but there is nothing to do with astigmatism!

Astigmatism is a medical problem in the world. At present, there is no absolutely effective method except wearing glasses.

Personally, I suggest that the operation is risky, and the choice must be careful!