Nothing makes you appreciate your vision more than getting a little older and realizing that it used to be better and that it will probably get worse. But imagine how much more difficult it would be if you were totally blind. That was what happened to [Berna Gomez] when, at 42, she developed a medical condition that destroyed her optic nerves leaving her blind in a matter of days and ending her career as a science teacher. But thanks to science [Gomez] can now see, at least to some extent. She volunteered after 16 years to have a penny-sized device with 96 electrodes implanted in her visual cortex. The research is in the Journal of Clinical Investigation and while it is a crude first step, it shows lots of promise and uses some very novel techniques to overcome certain limitations.
The 96 electrodes were in a 10×10 grid with the four corner electrodes missing. The resolution, of course, is lacking, but the project turned to a glasses-mounted camera to acquire images and process them, reducing them to signals for the electrodes that may not directly map to the image.
Continue reading “Brain Implant Offers Artificial Vision To The Blind”
Of all the things evolution has stumbled across, the eye is one of the most remarkable. Acting as sort of a ‘biological electromagnetic transducer’, the eye converts incoming photons into electrical and chemical spikes, known as action potentials. These spikes then drive the brain of the host life form. Billions of years of natural selection has produced several types of eyes, with some better than others. It would be an honest mistake to think that the human eye is at the top of the food chain, as this is not the case. Mammals underwent a long stint scurrying around in dark caves and crevasses, causing our eyes to take a back seat to other more important functions, such as the development of a cortex.
There are color sensitive cones in all eyes. Mammals have three types of cones, which are…wait for it…Red, Blue and Green. Our red and green cones are relatively recent on the evolutionary timescale – appearing about 30 million years ago.
The way these cones are distributed around our eyes is not perfect. They’re scattered around in lumpy, uneven patterns, and thus give us an uneven light sampling of our world. Evolution simply has not had enough time to optimize our eyes.
There is another animal on this planet, however, that never went through “the dark ages” as mammals did. This animal has been soaring high above its predators for over 60 million years, allowing its eyes to reach the pinnacle of the natural selection process. A bald eagle can spot a mouse from over a mile away. Birds eyes have 5 types of light sensitive cones – red, blue and green like our own. But add in violet and a type of cone that can detect no light, or black. But it is the way these cones are distributed around the bird’s eye that is most fascinating, and the subject of today’s article.
Continue reading “Hyperuniformity — A Hidden Order Found In The Greatest Set Of Eyes”
[Gregory McRoberts] was born with reduced vision in one eye and has never experienced the three dimensional sight which most of us take for granted. Recently he was inspired by the concept of a hearing aid to build a device which can augment his vision. Behold, the very Borg-like eye-patch that he wears to add distance and heat to his palette of senses.
The hardware he chose is an Arduino-compatible Lilypad board. It is wired to an ultrasonic rangefinder and an infrared sensor which monitor the area in front of him. The function of his right eye is still capable of seeing light and color, so a pair of LED boards are mounted on the inside. One is connected to the thermal sensor, displaying blue when below eighty degrees Fahrenheit and red when above. The other LED is green and flashes at a different speed based on the range sensor’s reading.
This is distracting when a person with normal sight wears it because of the intensity of the LEDs. We found [Gregory’s] explanation of this (called Helmet Fire) quite interesting.