The human body, alas, tends to degrade with age. As we get older our waistlines expand, our memory worsens, and senses like hearing and sight can often diminish, thanks to a range of different complaints. When it comes to eyesight, the most common cause of loss of vision is a condition called macular degeneration, the leading cause of blindness for those over 50. As you might imagine, patients with macular degeneration have problems when it comes to that great American pastime, watching TV. But that might soon change, thanks to the work of some researchers at Schepens Eye Research Institute in Boston, MA.
Macular degeneration is a disease that affects the center of the retina (or macula), the part of the retina that is responsible for fine detail in the center of our focus. Central vision begins to become blurry and distorted, and eventually a blind spot forms. This grows, distorting peripheral vision until sight is lost. Obviously that makes actions such as reading or watching TV more than a little difficult, yet patients with this disease are no less likely to enjoy these activities than you or I.
Now, thanks to research from a team of scientists in Boston, patients with macular degeneration may be able to look forward to settling in for the evening with their digital TVs and American Idol. This is possible thanks to the development of a filtering algorithm that increases the contrast on an MPEG-2 stream in real time, with the result that patients suffering from macular degeneration have a much better chance of discerning the image. Unlike simply boosting the contrast control on your TV, this technique specifically increases contrast over a range of spatial frequencies that people with vision problems have trouble seeing.
24 patients with diminished vision and six healthy control subjects were given a remote control that altered the level of contrast enhancement, and were shown a series of videos. The volunteers could increase the contrast to the point at which the image was most watchable to them. Even the control volunteers reported that increased contrast made the image more easily viewable, and for the vision-impaired, it was found that those with worse sight preferred the highest contrast increase. You can see an example of this filtering in this movie clip.
The lead investigator of this study, Dr Eli Peli, is now working with Analog Devices Inc. to create a chip that could be added to TVs to aid people with affected eye sight. Dr Peli confirmed that the technology is also being adapted to work with newer compression formats such as MPEG-4 and H264, and that interestingly, the results with H.264 were even more promising.