Astigmatism and strabismus can sometimes be corrected, depending on their severity. Astigmatism refers to the condition where parallel light rays entering the eye cannot focus on a single point on the retina after being refracted by the eye's optical system, instead forming two focal lines, ultimately failing to produce a clear image on the retina. Astigmatism can be categorized into regular and irregular types. Regular astigmatism can be corrected with cylindrical lenses in eyeglasses; while irregular astigmatism generally requires correction with contact lenses. Additionally, after reaching 18 years of age, astigmatism can also be corrected through refractive surgery. Generally, mild astigmatism does not impact vision and does not require special treatment; however, moderate to severe astigmatism, if uncorrected, might lead to amblyopia and other vision impairments. Strabismus means that when one eye is focusing, the visual axis of the other eye deviates from being parallel, presenting an abnormal eye position. It is generally recommended to start treatment immediately after diagnosing strabismus. If there is significant refractive error, glasses should be prescribed first. If glasses cannot correct the condition, surgery might be necessary.