Silicone lengthening of the superior oblique muscle is a semi-quantitative surgical procedure for superior oblique muscle reduction, which was proposed by Wright in 1991. It is now relatively effective in controlling the prognosis of diseases in which the superior oblique muscle is hyperactive and limited, such as Brown’s syndrome, type A strabismus and superior oblique muscle hyperactivity, compared to tendon severing and wire hanging of the superior oblique muscle. This procedure is also being performed in China. For me, it is important to choose the right case and to perform the silicone lengthening of the superior oblique muscle under a microscope with more care and precision, especially when dealing with the suture connection between the silicone and the tendon.