* To protect his eyes from the sun. Lynne is frequently photographed outdoors, and sunglasses can help to protect his eyes from the sun's harmful UV rays.
* To make a fashion statement. Sunglasses can be a stylish accessory, and Lynne may simply enjoy the way they look.
* To hide his emotions. Sunglasses can conceal a person's facial expressions, which can be useful if Lynne wants to avoid revealing his feelings in public.
* To create a mystique. Wearing sunglasses can make a person seem more mysterious and intriguing, and this may be something that Lynne enjoys.
Of course, only Lynne himself knows for sure why he wears dark glasses. It is possible that he wears them for a combination of reasons.