Tag Archives: Eye


The DOE Artificial Retina Project is a multi-institutional collaborative effort to develop and implant a device containing an array of microelectrodes into the eyes of people blinded by retinal disease. The ultimate goal is to design a device with hundreds to more than a thousand microelectrodes. This resolution will help restore limited vision that enables reading, unaided mobility, and facial recognition.

The device is intended to bypass the damaged eye structure of those with retinitis pigmentosa and macular degeneration. These diseases destroy the light-sensing cells (photoreceptors, or rods and cones) in the retina, a multilayered membrane located at the back of the eye.

Biomedical scientists give man his sight back

Diseases and conditions where stem cell treatm...
Image via Wikipedia

Stem cell research carried out by biomedical scientists has enabled a man who was left partially sighted after intervening in a fight to recover his vision.

In 1994, Russell Turnbull lost most of the sight of his right eye after being sprayed in the face with ammonia while trying to break up an altercation on a bus, the Times reports.

The 38-year-old was left with pain, extreme sensitivity to light and cloudy vision.


Both Light and Sound Have Oscillating Waves

Velocity Travels Through Vacuum? Wavelength Frequency
Light 186,000 miles/sec
(300,000 km/sec)
in vacuum
Yes 400-700 nm 4 X 10^14
to 7 X 10 ^14
Sound About 700 mph
(about 340 m/sec)
(1 mile per 5 seconds)
in air
No .02 to 20 meters 20-20,000 cycles/sec
  • Sound and light are waves in which the amplitude oscillates with time
    • For pure tones or colors the oscillation is a sine wave with a fixed wavelength and frequency
    • The wavelength is the distance between 2 peaks of the wave