I run 4-5 days a week in the Texas heat, so a good pair of sunglasses is important.  I've tried several different brands, but they were either too dark, too heavy, or constantly slipping down my nose from sweat.  I considered a $150 pair of Oakley's, but decided to try the JiMarti's first because of the great price and good reviews.  Glad I did.  Although the mirrored finish appears to be very dark from the outside, the lens is actually light enough to allow me to easily detect uneven surfaces on pavement and trails.  Even on a sweaty run, the rubber nose grip prevented them from slipping even once during an almost 2 hour run in the heat.  The flexible wrap-around design gives them a good fit for a variety of different size heads.  I was so happy with mine that I ordered a pair for my 12 year old son for baseball, and a pair for my husband for golf.  They fit my son perfectly.  My husband has a very large head, and although he could have used a slightly wider lens design, he is still happy with them for the price.  We ordered the black frame/blue lens, red frame/smoke lens, and silver frame.  The silver frames, in my opinion, look a bit cheesy, but both the black and red frames look like quality pairs of sports glasses.