Using Google Glass for long periods of time can lead to eye fatigue and headaches.

"As we note in our Help Center, Glass is designed for micro-interactions, not for staring into the screen, watching Friday night movie marathons or reading 'War and Peace,'" a Google spokesperson told CNET after consumers complained on Twitter and in blog posts.

An optometrist hired by Google to advise the company on building the device said placing the product's display component in front of the eye during production caused issues for the tech giant.

"The only people who look up a lot are some professionals like electricians and painters," Dr. Peli told Betabeat. "Most of us look either straight or down. It's well known that up is less comfortable."

One Twitter user said he felt discomfort each time he donned the device.

"Personally, it gives me a headache everytime I wear it. Not to mention, the eye damage all that squinting is likely to cause," Twitter user Jack Smith IV said in a post.

Google Glass lets consumers search the Internet, record video and even play games like virtual tennis. A balancing challenge evaluates one's ability to keep books on their head, while a clay shot game mimicks the famous duck hunt game.

The Match feature evaluates how well users pair patches with similar patterns, while a Shape Splitter breaks up shapes, a recent Google blog post read.

Glass' music capabilities allow users to look for songs, review playlists and hear tunes in good quality sound.

The device's new operating system Android KitKat gave consumers more battery power upon its release.

Google said Glass will remain available as long as supplies last. Those interested in purchasing the device should enroll in the company's Explorer program.

"We learned a lot when we opened our site a few weeks ago, so we've decided to move to a more open beta. We're still in the Explorer Program while we continue to improve our hardware and software, but starting today anyone in the US can buy the Glass Explorer Edition, as long as we have it on hand," Google said in a post.