In fact, there are many sunglasses are not limit for gender. Both men and women can wear it. Some people called it unisex sunglasses. Of course, there are some male sunglasses or female sunglasses. Anyway, if the sunglasses looks good on you, just try on. You know, rayban aviator sunglasses that are generally considered wearing cool for men and originally designed for men. But still lots of women wear it. So, It is really hard to see what features of sunglasses are for men.
There are no obvious features of male sunglasses. Compared to female sunglasses, sunglasses for men tend to be larger and simpler because men tend to have larger faces than women. Most women sunglasses have more designs and patterns on them to make them look more feminine. While male sunglasses don't have these unconventional patterns. They just resemble standard glasses. Besides, sunglasses for men usually come in simple colors, such as black, brown and grey.