jump to navigation

What is Flickering? or the Flicker Rate? October 5, 2006

Posted by healthyself in 16-25 Hz, 3-60 Hz, 50 Hz, 60 Hz, Adolescents, Bioeffects, Biological Effects, Blogroll, Cell phone safety, Cell Phones, Children's health, Chromosomal damage, Chronic Fatigue, Definitions, Electrical Components, Electrical Pulses, Electrical Wiring, Electromagnetic Communications, Electromagnetic pollution, Electromagnetic waves, EMF's, Environment, Epilepsy, Exposure, Eyes, Flickering, Frequencies, GHz, Health related, HOuseholds, Hz, Interdisciplinary, Lifestyle, light beam, nerves, Oscillate, Photosensitive, Pulsed Radiation, radiation, School administrators, Spacial Contrast Patterns, Symptoms, Teenagers, Telephony, Toxic Interactions.
trackback

Flickering is the opposing changes in intensity of luminosity. This is usually caused by flashing, but can also be caused by spatial contrast patterns that oscillate at dangerous frequencies; the type of images that people create to deliberately stimulate a response in the recipient that makes them believe the image is moving or changing. For people with photosensitive epilepsy, flickering causes many of the nerve cells that process visual stimuli to all fire at once, resulting in a seizure”

“Along with the frequency of the flickering, the size and luminous intensity of the stimuli is significant for people with photosensitive epilepsy. The greater the intensity and larger the size of the stimuli, the greater the danger of provoking seizures caused by flickering at dangerous frequencies.”

“The colour red is particularly dangerous due to its longer wavelength that stimulates cones in the retina. There have been cases where photosensitive epileptic seizures have been triggered by cyclists while setting up the red flashing rear lights on their bicycle. Even when there is no perceived difference in the luminosity of the contrasting colours, red flickering is far more likely to cause seizures than other colours.”
“Television programmes are thought to be the most common cause for triggering photosensitive epileptic seizures. The most famous incident of photosensitive epilepsy caused by a television programme is the Pokémon episode, Electronic Soldier Porygon , which was aired in Japan in 1997. Nearly 700 children were admitted to hospital through photosensitive epilepsy that was thought to have been induced by the episode.”

People with photosensitive epilepsy can have seizures triggered by flickering or flashing in the 4 to 59 flashes per second (Hertz) range with a peak sensitivity at 20 flashes per second as well as quick changes from dark to light (like strobe lights).When content violates either the general flash threshold or the red flash threshold , users are warned in a way that they can avoid it

Content does not violate the general flash threshold or red flash threshold

“Allowing people to choose whether or not they receive the content is better than not providing a warning, but there are other factors to consider. The first is that as photosensitive epilepsy is most common in children, it could be that they don’t understand or appreciate the significance of the warning. It isn’t just children; people with reading difficulties or speakers of languages other than the language of the warning may also inadvertently be exposed to content that could induce seizures.”

“Although the size of the stimuli is significant, there is still a danger of material that is considered to be safe being changed by the visitor. For example, low vision users increasing the size of flickering material, or someone leaning in close to the screen.”

“The safest way to avoid causing photosensitive epilepsy is to completely avoid creating web content that flickers.”

“People with photosensitive epilepsy who suddenly find themselves exposed to material that could trigger a seizure should immediately cover one eye with the palm of their hand to reduce the number of brain cells that are stimulated by the flickering content, and either close the page or navigate away from the page.”

“Photosensitive epilepsy is a form of epilepsy that is triggered by visual stimuli, such as flickering or high contrast oscillating patterns, and it’s believed that around 3% to 5% of people with epilepsy are susceptible to photosensitive material. Photosensitive epilepsy is usually triggered where the flicker rate is between 16Hz to 25Hz, although it’s not uncommon for seizures to be triggered by flicker rates between 3Hz to 60Hz. The condition most commonly effects children, and is usually developed between the ages of 9 and 15 years, and most prevalent in females.”

Advertisements

Comments»

1. rita - March 7, 2008

Cam this filickering also come from digitalized movies and LCD tvs? Is there any known eye therapy for this condition?

2. Rand Paul rocks Energy & Natural Resources committee meeting! - Democrats, Republicans, Libertarians, Conservatives, Liberals, Third Parties, Left-Wing, Right-Wing, Congress, President - Page 8 - City-Data Forum - June 9, 2011

[…] […]

3. spookfu - May 20, 2012

Reblogged this on spookfuey and commented:
understand the tone is a same thing as a freq. mw are tone that is too high for you to hear and the rest you may know


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: