Yes, most online optical stores have the try-on system for customer to try on any sunglasses on their face by uploading a picture of yourself and putting on the sunglasses on that picture. You can see the image directly and compare among different pairs. Just visit a reliable online optical store, follow the instruction of Try-on.
Some online optical stores allow you to try glasses on to see whether they will look good on you. If you find the sunglasses you like, you can click the try-on button just below the picture and then you are asked to upload a photo of yours. Then you will see the effect that you try them on.
I also don't know we can try sunglasses online until I find Firmoo.They provide a convenient and easy-to-use virtual try-on system for you to see how you look with different sunglasses. You just need to upload a picture of your frontal face.You can have a look.