Featured Research

from universities, journals, and other organizations

Artificial retinal implants must adapt to unique features of human eye to be effective, experts say

Date:
April 28, 2011
Source:
Institute of Physics
Summary:
A professor of physics, psychology and art warns that artificial retinal implants -- a technology fast becoming a reality -- must adapt to the unique features of the human eye in order to become an effective treatment.

In the May issue of Physics World, Richard Taylor, professor of physics, psychology and art at the University of Oregon, warns that artificial retinal implants -- a technology fast becoming a reality -- must adapt to the unique features of the human eye in order to become an effective treatment.

Related Articles


The gap between digital camera technology and the human eye is getting ever smaller, in terms of both the number of light-sensitive detectors and the space that they occupy. A human retina typically contains 127 million photoreceptors spread over an area of 1100 mm2. In comparison, today's state-of-the-art CMOS sensors feature 16.6 million photoreceptors over an area of 1600 mm2.

Despite the impressive progress of camera technology, several differences still remain, which is why, Taylor states, camera technology cannot simply be incorporated into the eye to restore the vision of patients with damaged rods and cones.

Taylor highlights that the eye tends to see what is directly in front of it -- as the majority of its seven million cones are concentrated centrally -- and less so on the periphery, whereas a camera captures everything in uniform detail with its pixels spread evenly across its entire field of view.

As such, the eye has to continually scan small areas to ensure that the image of interest falls mainly on the fovea -- a pin-sized region positioned directly behind the lens that is crucial when visualizing detail. This is because the human eye exploits fractal patterns -- geometric shapes that are present throughout nature and repeat themselves down to the smallest scale. If the eye employed the uniform distribution of photoreceptors found in cameras, there would simply be too much information for the brain to process in real time.

Furthermore, Taylor states how certain natural fractal patterns such as clouds, trees and rivers are more aesthetically pleasing and can greatly reduce stress. This stress-reduction process would not occur with a camera-based implant as movement in the eye would become unnecessary, eventually leading to the eye learning not to move and therefore not activating the relevant areas of the brain to relieve stress.

As Taylor writes, "Remarkably, implants based purely on camera designs might allow blind people to see, but they might only see a world devoid of stress-reducing beauty. This flaw emphasizes the subtleties of the human visual system and the potential downfalls of adopting, rather than adapting, camera technology for eye."

In addition to the problem of photoreceptor distribution, Taylor also highlights the problem of connecting an implant's electrodes to retinal neurons, which are fractal in structure and tend to stay intact even if the eye's rods and cones themselves are damaged by disease. A solution to this, developed by Taylor and his colleagues, is nanocluster deposition.

This involves the delivery, through an inert gas, of nanoclusters of materials onto the photodiodes of an implant. These clusters then self-assemble into the required fractal shape and enhance the connection between retinal implants and healthy neurons while at the same time allowing light to pass through onto the photodiode.


Story Source:

The above story is based on materials provided by Institute of Physics. Note: Materials may be edited for content and length.


Cite This Page:

Institute of Physics. "Artificial retinal implants must adapt to unique features of human eye to be effective, experts say." ScienceDaily. ScienceDaily, 28 April 2011. <www.sciencedaily.com/releases/2011/04/110427194858.htm>.
Institute of Physics. (2011, April 28). Artificial retinal implants must adapt to unique features of human eye to be effective, experts say. ScienceDaily. Retrieved March 5, 2015 from www.sciencedaily.com/releases/2011/04/110427194858.htm
Institute of Physics. "Artificial retinal implants must adapt to unique features of human eye to be effective, experts say." ScienceDaily. www.sciencedaily.com/releases/2011/04/110427194858.htm (accessed March 5, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, March 5, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Bupa Eyes India Healthcare Opportunities

Bupa Eyes India Healthcare Opportunities

Reuters - Business Video Online (Mar. 5, 2015) Bupa is hoping to expand in India&apos;s fast-growing health insurance market, once a rule change on foreign investment is implemented. The British private healthcare group&apos;s CEO tells Grace Pascoe why it&apos;s so keen on the new opportunity. Video provided by Reuters
Powered by NewsLook.com
Doctor in Your Pocket Is Getting Smarter

Doctor in Your Pocket Is Getting Smarter

Reuters - Business Video Online (Mar. 5, 2015) Mobile apps are turning smartphones into a personal doctors, with users able to measure heart rate, blood pressure and even blood sugar. But will it change our behaviour? Ivor Bennett reports from the Mobile World Congress in Barcelona. Video provided by Reuters
Powered by NewsLook.com
AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

AbbVie Inks $21B Deal To Buy Cancer Drugmaker Pharmacyclics

Newsy (Mar. 5, 2015) AbbVie announced Wednesday it will buy cancer drugmaker Pharmacyclics in a $21 billion deal. Video provided by Newsy
Powered by NewsLook.com
Adults Only Get The Flu Twice A Decade, Researchers Say

Adults Only Get The Flu Twice A Decade, Researchers Say

Newsy (Mar. 4, 2015) Researchers found adults only get the flu about once every five years. Scientists analyzed how a person&apos;s immunity builds up over time as well. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins