It is hard to see. If your myopia is not too strong, you can try prescription sunglasses to shield your eyes in sun and help you get clear vision. But if you have a very strong myopia usually over -/+6.00, you are not recommend to wear prescription sunglasses. So, i don't know which type of sunglasses may be good for you. Perhaps, you can try to fitover sunglasses. Hope this help you.
As you say, you are high myopia. Typically, you can choose to have prescription tinted sunglasses or coated lenses. Now the coated lenses, which are to say, colored sunglasses plus film, and they are more and more popular. In addition, they can also fight against to the reflective light, prevent ultraviolet and so on. But, as you belong to a strong prescription, you need to choose a high refractive index lenses and a smaller frame so that the lenses are relatively thin and more beautiful. At the same time, you also can be equipped with a transition lenses. They are based on the change in the strength of the ultraviolet. If there is not ultraviolet indoor, they are no color. They are almost normal myopic lenses indoor, but if not, they change faster. According to your preferences, you can choose different styles of sunglasses and I wish you a pleasant.