It depends on your demand. Here are some information to help you make a choice:

-Material: Most frames are made of metal or plastic or mixed material. Metal frame is usually lighter while plastic frames are more durable. And acetate is durable and unlikely to cause skin irritation.

-Weight: If you want an extreme light frame, select frames of 15 grams or lower. Titanium frames are usually very light.

-Color: Metal frames are usually gold, silver and black. But plastic frames may have more color options.

Hypoallergenic: Stainless steel, acetate and titanium frames are hypoallergenic.