Eyewear is often used in outdoor sports to provide protection against the ultraviolet rays. For some sports or outdoors activity, they are essential equipment as losing it may risk eye injury from intense sun's ray. Most sunglasses and shades are designed with straight temples for easy put on and take off but that also makes it easy to fall off on impact. The fit of straight temples is also less tight compared to skull temple eyewear (unless you find one that perfectly follows the contours of your head) which makes them more likely slip under heavy perspiration. Means of securing the eyewear is thus an important consideration.
Adjustable eyewear cord.
The most common means of securing eyewear is using spectacle straps. These are typically attached to the tip of the spectacle temple and goes round the back of the neck. The eyewear strap may hang loosely at the back of the head or tightened to fit round the back of the head. Putting on and removing the eyewear with a loosely hung, fixed-length strap is easy. There are fixed-length straps that are elastic which can be stretched to put over the head and return to shorter length when released. The eyewear may also be hung round the neck when not in use. While the risk of it getting caught may be low, the dangling strap may cause the eyewear to see-saw up and down if the temple of the eyewear is not holding tightly to the head. Depending on the design, the extra length behind the head may also interfere with jacket hood, helmet or any head gear.
Adjustable eyewear straps are better at securing the eyewear with less movement when the head is moving. The disadvantage is that it is necessary to adjust the length of the straps each time the eyewear is put on or taken off. Some users may keep the strap sufficiently loose so that it can still be taken off or put on without further adjustment to the strap. More recent designs such as Speccles require only one time adjustment of the length. For Speccles, releasing of the strap is by detaching one end from the end of the temple.
Eyewear straps for water sports typically have an additional feature beyond securing of the eyewear. They are able to float on water with your eyewear for easy retrieval. That is assuming that the eyewear is not washed away by rapid water current. Basic floatable straps may be made out of light-weight material that can float on water such as neoprene. This is probably sufficient for keeping light-weight eyewear on the surface. For heavier eyewear (especially prescribed glasses/spectacles) or water sports in rougher water, a strap that comes with a light floatation device is recommended.
Eyewear straps are very effective for securing spectacle. There are many designs available in the market with some providing better fit and comfort. Although better designs may come at a slightly higher price, eyewear straps are generally long-lasting and the cost of it is much less than getting a replacement eyewear.
Sports Spectacle Hook
Spectacle hook is typically used for preventing spectacle from slipping down the nose and more recent design is able to hold the eyewear better than eyewear straps/cords. Spectacle hook is also generally more comfortable than eyewear band as they do not cause the eyewear to see-saw up and down. It is also better at keeping the eyewear from slipping down your nose for better concentration. Once inserted, the eyewear may be put on or taken off without further adjustments. Wedge Classic spectacle hook from Beta-Simplicity features a curved hook that goes round the back o the ear which provides better all round anchorage of the eyewear. Unlike most spectacle hooks which are difficult to slip onto the temple, this design is easy to slip on and off, as and when required. However, the main downside of spectacle hook is that if the eyewear gets knocked off from your face, there is no stopping the eyewear.
Wedge Classic from Beta-Simplicity (Image courtesy of Beta-Simplicity)