Myopia cannot be eliminated or reduced in magnitude. This is because true myopia is caused by a deformation of the eye (elongation of the eye axis). It is not possible to shrink back an eye that has already grown larger. For myopia itself, the only way to correct it is with glasses. High myopia has many possible complications, the most common of which is vitreous opacity. Cataracts can also occur (which will not be evident at your age yet). Some medications can be tried under medical supervision to improve the symptoms. The most serious complication is retinal detachment, which is characterized by black shadows in front of the eyes, flashing sensation, and obscured vision, etc. You need to go to the hospital for fundus examination and ophthalmic ultrasound. It is necessary to avoid strenuous activities (such as jumping and coughing) to prevent retinal detachment.