Summarize this article:

You might find that certain colors are more comfortable for your vision than others. While shopping for new sunglasses, you should try on pairs with various lens colors. Many opticians and sunglass stores will carry lenses in various shades that you can try on. You may find that there are certain differences between these colors, such as:  Gray, brown, and green lenses are neutral. They decrease glare and eyestrain without distorting colors. Yellow, amber, and orange lenses increase contrast, but they may distort color. They also block out blue light, which some believe may be harmful for the eyes. Red or rose tinted glasses increase contrast, but they distort color more strongly than other shades. Photochromic lenses are those that change colors based on how much light they are absorbing. These glasses can adjust from bright conditions to dim ones, although they do take a few minutes to adjust. They are also more expensive than a normal pair of prescription glasses, although they eliminate the need for a separate pair of sunglasses. If you wear prescription glasses, you might consider investing in a pair so that you do not have to switch between glasses in middle of activities such as driving. Typically, photochromic glasses will darken into neutral colors such as gray. You should aim for a tint that is about medium darkness; if you can see your eyes when looking in a mirror, they may not be dark enough. You do not need to buy the darkest lenses unless you live in a very bright area. Darker lenses do not necessarily block more UV rays, but they may make it more difficult for you to see. It is important that you get glasses you can see clearly in. If you need different types of colors for different activities, you might consider buying a few pairs of glasses in different shades. You might have one pair for driving and another for sports. If you play several sports, you might find that you have a different pair for each activity.

Summary:
Try on different colors. Consider photochromic lenses. Go for medium darkness. Invest in several pairs.