The LEDs will notify you, when you are about to mess up.
Swimming in the sea, for example, where your path is not clearly marked, as it would be in a swimming pool, you easily deviate from your intended course. It often happens that you do not swim directly towards your destination point, but you perhaps stray a little, so your swim proves to be longer and more time consuming than you expected. Which is perfectly ok, when you think of all the exercise, benefiting your body, but at the same time absolutely terrible, if you are racing against time (or other swimmers).
On Kickstarter there is a crowdfunding campaign for very special navigation goggles, which are designed to keep you swimming in a straight line even in open water. They prevent you you from zig-zagging aimlessly and, if you are an athlete, help you improve your personal record. The device is called OnCourse Goggles, the ultimate gadget for recreational and professional swimmers alike..
OnCourse Goggles contain an embedded high-precision electronic compass, accelerometer with tilt compensation, a seriously tiny microprocessor, rechargeable battery and developers' own software. The goggles are incredibly easy to use. You set the direction you want to go just by looking at your destination point and hitting a button on the side of the goggles. If you happen to veer too far off intended course, a small LED will light up above your eye (at first it will glow yellow, then red) and indicate which way you should continue. If you wish to set a new course, once the initial checkpoint has been reached, you just set another target, look in that direction and press the button.
The glasses will come in two sizes, because the developers believe, this is no one-size-fits-all matter. Swimmers, inclined to having glasses that boss you around (with good intentions, though), will be able to purchase them for 199 dollars.