BY BARBARA ORTUTAY and RYAN NAKASHIMA

Associated Press

LAS VEGAS

Many of the prototypes introduced at the annual gadget show over the years have failed in the marketplace. But the innovators who shop their wares here are fearless when it comes to pitching new gizmos, many of which are designed to solve problems you didn't know you had.

A search for this year's strangest (and perhaps least useful) electronic devices yielded an extra-loud pair of headphones from a metal band, an eye-sensing TV that didn't work as intended and more. Take a look:

EYE-SENSING TV

A prototype of an eye-sensing TV from Haier didn't quite meet viewers eye-to-eye. An on-screen cursor is supposed to appear where the viewer looks to help, say, select a show to watch. Blinking while controlling the cursor is supposed to result in a click. In our brief time with the TV, we observed may quirks and comic difficulties.

HAPIFORK

If you don't watch what you put in your mouth, this fork will--or at least try to. Called HAPIfork, it's a fork with a fat handle containing electronics and a battery. A motion sensor knows when you are lifting the fork to your mouth. If you're eating too fast, the fork will vibrate as a warning. The company behind it, HapiLabs, believes that using the fork 60 to 75 times during meals that last 20 to 30 minutes is ideal.

But the fork won't know how healthy or how big each bite you take will be, so shoveling a plate of arugula will likely be judged as less healthy than slowly putting away a pile of bacon. No word on spoons, yet, or chopsticks.

iPOTTY

Toilet training a toddler is no picnic, but iPotty from CTA Digital seeks to make it a little easier by letting parents attach an iPad to it. This way, junior can gape and paw at the iPad while taking care of business in the old-fashioned part of the plastic potty. iPotty will go on sale in March, first on Amazon.com.