I live in these shades during the summer bike season. they are light, tough and easy to swap out lenses which is critical during bike riding when your dealing with different weather, forest cover, and trail conditions.

I use these shades year round...summer biking and alpine climbing, winter ski touring. The mix of lenses are great, with a polarized sunglass lense, a clear one, and a rosey goggle type lens. I find myself using the rosey lens almost all winter in flat light skiing and in the trees as goggles are just too warm for me. But in the summer you can swap into the clear lens to keep the mud and grit out of your eyes for the coastal mountain biking I do. I found these things pretty darn durable, and even when I did manage to beat them up a bit too much, Smith replaced them no questions asked!

Great pair of shades, love the shape of the lenses. Durable as just about anything, even lost them momentarily in a river while tubing and they came out looking grand. One issue though, the frame is tight on the lenses when not worn, but when I put them on, the slight tension on the side arms of the frames opens the frame around the lenses on one side just a tad. Not so much as the lense could fall out, just a bit. I only notice it when adjusting the glasses on my face, as I can squeese the frame tight around the lense and it makes a little popping noise.

For the price it comes with a really nice case...unlike some brands in this price range...*cough* *oakley* *cough*

the sunglasses are very well-crafted and very durable. for this shades, it has a rubber grip on the side that holds to your head...makes the grip to your face even better.

The shades is a little tight for me in the beginning...gets better though...although i know i would opt for a "Large" size for my next Smith Optics shades.

i would really recommend visiting a local sunglass store to check out the size then buy it here!...unfortunately, not a lot of local stores don't stock Smith Optics sunglasses...let alone this particular model.

The 3 included lenses are awesome if your like me and you scratch them easily. The case is also high quality. Smiths are on SAC all of the time so get a deal on there. They are a tad loose on me which is different than other smiths that I have. These shades give good eye coverage but not that insane bug eyed look that you may not be cool enough to pull off. I recommend these but not for retail price. Don't pay more than $75.

Really awesome shades and fit my face perfectly. I have a tough time sometimes with sunglasses but these are really perfect. The Interlock system is really cool being able to switch lens on the fly in just seconds. Awesome!

I bought these 4 months ago and they've become my all-time favorite. Lenses are quickly changed, giving me the options I need. These shades stay put, working perfectly in the boat, on the bank, or wherever.

I've had the Interlock Trace for about a month now. The Interlock lens changing system is far superior to the Slider system. The Interlock is easy to use and makes lens changes quick. The polarized lens are a great addition to the glass. The clear mirror and ignitor lenses are better than the rose and yellow lenses of old. I use the ignitor lens for low light situations almost as much as I use the polarized lens for on bright days. The temple pieces have rubber grips which help hold the sunglass in place while biking, running, or ski touring. I am 100% happy with these sunglasses and would recommend them to anyone.

Interlock are the highest quality Smith sunglasses I have owned. While the frame style is not ideal for sports the interlock functions flawless. Polarized lens are a nice add.

The interchange system with these shades is great. It is so easy to change lenses I find myself actually changing lenses a lot, which is a good thing since I paid the extra cash to get an interchange system.

I really enjoy these glasses. They are comfortably and stay on my face skiing or bending down in the stream. One thing to consider they do have interchangeable lenses, but to buy other polarized replacements can get pricey. I bought the traces with the polarized grey lenses and they don't work great for fly fishing as they are too dark. The photochromic copper replacement lenses are $70.00 retail. So when buying these glasses make sure you get the lenses you want the first time.

If I was a castaway on a deserted island and could only bring a single pair of glasses these would be them. Super versatile, great for anything active but still stylish enough to fit in around town. The interlock system makes changing lenses a breeze and the polarized feature is always nice. I wear mine (the wood tort frame) trail running and they stay put even when I work up a sweat. Just another fantastic pair of glasses from Smith.

These were my boyfriends, but he left them at my house one day and now they are mine, hahaha. They have nice full coverage for mountain biking (which is what i use them for), the wood tort frame looks pretty cool, and polarized is always nice to have. I thought the brown was too warm/brown/orange at first, but once your eyes get used it, they are great. They fit great and stay on during biking just fine. overall i have a medium sized head for comparison.