Soon, many people will be seeing the world through computerized glasses, and not just those made by Google.
Spurred by the coming of Google Glass, a handful of companies are joining the nascent market to float email, text messages and the Internet in front of people as they ride their bicycles, buy groceries or pretend to be paying attention at meetings.
Many of the new glasses from Google rivals will have a different look from Glass and be aimed at specialized markets, said Shane Walker, an analyst at the research firm IHS, who is preparing a report on an expected surge in smart glasses and related products.
Recon Instruments, for example, has engineered smart sunglasses designed for the tough wear and tear of triathlons and other harsh situations that may not be suitable for the more sedately styled Glass. Recon's sunglasses, called Jet, display heart rate and other physical data, as well as step-by-step directions if cyclists become lost on the way to a race.
The double-decker SpaceGlasses from Meta have two projectors -- one for each eye. (Glass has one projector.) The two projectors can create 3-D images of virtual objects like keyboards that hang like holograms in midair in front of the wearers. Then, with the help of a hand-tracking feature, wearers can type on a virtual keyboard or play virtual chess. A lot of the new glasses will have features similar to those of Google Glass, including text notification and hands-free photography.
Critics have raised concerns that computerized eyewear will become yet another technological distraction -- a way for people to choose the virtual world over the real one.
"They won't be the best thing to wear when you're at a party," said Clive Thompson, author of "Smarter Than You Think: How Technology Is Changing Our Minds for the Better."
But Thompson says he thinks the coming generation of smart glasses will offer unusual benefits, too, as apps are written that let them display not just texts, email and newsfeeds, but also a range of useful data alongside what people are viewing in the real world. Mechanics peering into a car engine to repair a carburetor, for example, might see a virtual page from a manual or a computer animation explaining which part should be adjusted, and by how much.
Thompson, who enjoys repairing old laptops, is looking forward to that kind of help.
"It would be wonderful if we could see that information at the moment we need it to help us solve complex physical problems," he said.