When purchasing sports sunglasses for the golf course, racquetball court or the the ski slopes, the one main consideration for improving your visual performance is lens tint. The color of the lens of your sunglasses is important for improving visual clarity while protecting your eyes from injury. The best tint for sport sunglasses varies depending on weather and lighting conditions. For example, the best sunglasses lens tint for playing Frisbee on a sunny day at the beach will be too dark for hitting a golf ball on an overcast or partly cloudy day. Lens color is a personal choice and doesn't affect how well sunglass lenses protect your eyes from UV light. Gray and brown are popular because they distort color perception the least. 
So be sure that the sunglasses, (including clear) have 100% UVA UVB coating for the best protection for your eyes. If you will be using your glasses for a sport which is near water or snow or reflective surfaces, polarization will give your eyes additional protection from glare.
If you participate in several sports or in a variety of lighting conditions, consider purchasing several sport sunglasses with different lens tints. You can also get sport sunglass frames which have interchangeable lenses, which are great for a variety of lighting and weather conditions.
Sports and safety lenses are made of impact-resistant poly-carbonate to protect eyes from fast-moving objects. Poly-carbonate also has built-in UV protection. Untreated poly-carbonate lenses, however, can easily become scratched. For this reason, virtually all poly-carbonate lenses for eyeglasses and sports eyewear include a scratch-resistant coating on both the front and back surface for added durability. 
Regular eyeglass frames are not rated for use as safety glasses and typically don't provide the type of eye protection needed for sports. DO NOT play sports while wearing an eyeglass frame that is not rated for sports eyewear! It is dangerous and can result in a serious eye injury if the frame breaks.
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LENS TINT GUIDE
Grey. Maintains true color and best used in bright conditions. Serves as a good universal lens. Used for all outdoor sports.
Yellow and Orange: These colors heighten contrast and bring out shadows, good for seeing bumps, better depth. Best used for foggy overcast days and stormy conditions. Does not filter bright sunlight. Sometimes referred to as a blue light blockers, night-driving lenses or a high definition lens. Does not filter bright sunlight.
Dark Amber Copper, or Brown: Particularly useful to improve contrast on grass and against blue skies. Brings out shadows and bumps. Good for days with bright conditions or moderate fog.
Green. Increases contrast and best used for foggy overcast days with stormy conditions.
Amber, Rose, and Red. Increases depth perception and good in flat conditions. Excellent for foggy overcast days and stormy conditions
Clear. Allows the most light. Perfect for a snowy conditions sunset and nighttime.
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WHICH LENS TO USE
Golf: Green, Amber, or Yellow.
Skiing, Snowboarding, Snowmobiling: Yellow, Orange, Amber, Rose or Red with Polarization is best.
Cycling:Yellow, Orange, Dark Amber, Copper or Brown.
Hunting: Yellow, Orange Amber, Rose or Red.
Shooting: Yellow or Orange.
Tennis: Yellow or Orange.
Baseball, Basketball, Paintball: Green, Dark Amber Copper or Brown.
Fishing and Water Sports: Dark Amber, Copper or Brown with Polarization is best.
Indoor Basketball, Handball, or Racquetball: Yellow or Orange