New Product Idea-Night Vision Contact Lenses

Someone is working on the concept, but I don't expect to see marketable products for some time yet.

http://news.discovery.com/tech/night-vision-cell-phone-eyeglasses.html

First comment on this article is one thing that I have always wondered about.. "If you use night vision goggles in a completely dark space, you will not see an image. NVGs are not IR devices.".. Are modern NVG's IR devices or do they need some amount of ambient visible light to work

Unfortunately, this article is a typical superficial puff-piece. "Night vision" is such a severely abused term that I prefer to state the specific technology used to enhance vision.

1) Starlight or "light amplification" devices use the tiny amount of ambient light and amplify it using a photomultiplier tube or an avalanche semiconductor device. There is no image if there is "zero" light present.

2) Near Infrared (~0.8 - 1.0 micron wavelength) devices can detect and convert the NIR spectrum (just below human vision) into a visible image. Most CCD imagers are capable of this, but SONY is famous for leaving out a NIR filter that other camera makers add. NIR imagers can take advantage of NIR emitters (like LED's) to illuminate a scene when no ambient light is present. You can perform a quick test of your own digital camera at home. Try viewing your TV remote "through" your digital camera. If your camera does not have NIR blocking filters, the optical pulses coming from the remote should appear as bright flashes.

3) Long Wave Infrared (LWIR) imagers, also popularly known as FLIR cameras, capture the deep Infrared (~5 - 15 micron wavelength) HEAT emitted from ALL objects above absolute zero temperature. No ambient light is needed as these imagers can see in total darkness. FLIR imagers are currently complex and usually require some form of cooling or temperature stabilization. Although size and prices are dropping, they are still relatively bulky and expensive.

The article is not really clear about which type of imager the new development is it is supposed to replace. I expect it will be a mix of 1) and 2) where ambient light and NIR are both captured and amplified to provide an image. Although HEAT images are mentioned towards the end of the article, I'm skeptical it will be able to work in the FLIR range. If they ARE able to work in the deep IR, that would be VERY COOL indeed! (pun intended )

During my days of working in glass we did lens for far IR to Microwave and sol purpose was to capture signal irrespective of environmental conditions. Then you do need converted to bring this out in visible range or put it in dot fashion with varying dot based on the target viewed.

This is interesting area and there is always energy in one wave length or other we emit heat and part of that converted to energy and we can use the emitter source to create return signal input and digitise to make the image. It is both glass-electronic and soft ware end up defining how good your image will be and you need will depend on the source of light you are working from no visible light to outer space

One thing is true that NVGs are IR devices and do need some IR light too to see things in dark.

So if there are night vision contact lenses- you still cannot see without IR light !!!!

If so, what kind of materials would be required??

Gold & lots of it!

I really don't see how LEDs - mounted on the surface of the eye - could form an image that is in focus.

You would also have the issue of the light source moving with your eye movement. If you have ever watched a "floater" you know how unnatural the apparent motion is.

So I see image projection goggles or glasses being miniaturized, but not replaced by contact lens projectors. I believe William Gibson wrote a story with a character with eyes permanently covered by screens.

I do see how LCD contact lenses could replace sunglasses. They would even have polarized filters. (Oh yeah, LCDs have to have polarized filters!)