3D imaging or stereoscopy is not a new invention, it has been
used for static photographs since the 1860's. This usually involves two
separate images being viewed by the eyes taken at different angles. In
the 1920's the first practical 3D films were produced and required the
wearing of red and blue 3D glasses for the first time. Going to 3D
movies has been a fad since the eighties and many have enjoyed seeing
movies in 3D (and sometimes 4D) but these films were not usually feature
films and only lasted for a few minutes. There were some movies that
utilized 3D for only certain portions that left the crowd a bit confused
and it never really caught on.
It is only today, in this day and age that the safety of one's eyes from the exposure to prolonged usage of 3D viewing has come into question. This is because in the past people were limited to how much 3D they view, which was very seldom. Today 3D imaging has seeped into a host of different technologies and varying forms of media. From feature length films, video game consoles, televisions and even computers there is more and more exposure to virtual 3 dimensional media. This has prompted some to question the safety of prolonged usage of such technology.
There are three popular means to view 3D images;
· Color anaglyphs use two different colored lenses for each eye to perceive the 3D images. The film then has red and blue sections that correspond to the colors of the glasses to project a 3 dimensional images. This leaves some discoloration to the film but is effective nonetheless.
· Polarized 3D uses a similar system as color anaglyphs, but instead of using two different colors the separation is based on the direction of the polarized light dedicated to each eye. One is vertical while the other is horizontal and one cannot see the other. This leaves the color tone natural but in older straight polarized 3D glasses the head had to be pretty level for the 3D images to come in clearly.
· Active shutter system uses expensive glasses with LCD elements within the glass, an electrical impulse from the glasses turns them dark obstructing the view from the eye. By quickly cycling from one to the other 3 dimensional imaging can be achieved by having the movie frames switching at the same frequency. The glasses must be in complete sync with the movie for the 3D effect to work.
With these three different forms of 3D glasses there are different questions asked by those who may believe that 3D glasses are harmful to optical health. With color anaglyphs the question is in color correction. It is not advisable for people to walk around with color anaglyph glasses when not viewing a movie as the difference in color in the normal world may strain the visual cortex as it struggles to bring color correction to what is being perceived. Polarized 3D glasses pose the least risk to ocular health due to the fact that everyday millions of people around the world are wearing polarized sunglasses. Polarization does not constitute a risk to sight. Active shutter systems if worn while not viewing a movie can disrupt one's perception of the world around them and may even trigger seizures in epileptics. It is highly advised for people to walk around with active shutter 3D glasses on.
One other threat to optical safety is the amount of visual stimuli the eyes as well as the visual cortex needs to process. Remember 3D movies are an illusion, a veil upon which our minds can be tricked into believing that flat objects have depth and volume. This takes incredible amounts of computing in the visual cortex to perceive. In fact every second the visual cortex process upwards of 40 gigabytes to render sight as a perceivable sense. Some argue that 3D glasses and 3D media aggravate this problem by overloading the visual cortex. This is why some manufacturers have warnings stating that 3D media should only be used for short amounts of time, perhaps an hour or so a sitting. Some may notice that after a long time of viewing 3D media they get a headache, this may be due to the over use of the visual cortex as it is being taxed heavily with visual data.
Since 3D media as a major media source is fairly new more research must be conducted to get conclusive data on the threat that 3D glasses may pose to eyesight.
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It is only today, in this day and age that the safety of one's eyes from the exposure to prolonged usage of 3D viewing has come into question. This is because in the past people were limited to how much 3D they view, which was very seldom. Today 3D imaging has seeped into a host of different technologies and varying forms of media. From feature length films, video game consoles, televisions and even computers there is more and more exposure to virtual 3 dimensional media. This has prompted some to question the safety of prolonged usage of such technology.
There are three popular means to view 3D images;
· Color anaglyphs use two different colored lenses for each eye to perceive the 3D images. The film then has red and blue sections that correspond to the colors of the glasses to project a 3 dimensional images. This leaves some discoloration to the film but is effective nonetheless.
· Polarized 3D uses a similar system as color anaglyphs, but instead of using two different colors the separation is based on the direction of the polarized light dedicated to each eye. One is vertical while the other is horizontal and one cannot see the other. This leaves the color tone natural but in older straight polarized 3D glasses the head had to be pretty level for the 3D images to come in clearly.
· Active shutter system uses expensive glasses with LCD elements within the glass, an electrical impulse from the glasses turns them dark obstructing the view from the eye. By quickly cycling from one to the other 3 dimensional imaging can be achieved by having the movie frames switching at the same frequency. The glasses must be in complete sync with the movie for the 3D effect to work.
With these three different forms of 3D glasses there are different questions asked by those who may believe that 3D glasses are harmful to optical health. With color anaglyphs the question is in color correction. It is not advisable for people to walk around with color anaglyph glasses when not viewing a movie as the difference in color in the normal world may strain the visual cortex as it struggles to bring color correction to what is being perceived. Polarized 3D glasses pose the least risk to ocular health due to the fact that everyday millions of people around the world are wearing polarized sunglasses. Polarization does not constitute a risk to sight. Active shutter systems if worn while not viewing a movie can disrupt one's perception of the world around them and may even trigger seizures in epileptics. It is highly advised for people to walk around with active shutter 3D glasses on.
One other threat to optical safety is the amount of visual stimuli the eyes as well as the visual cortex needs to process. Remember 3D movies are an illusion, a veil upon which our minds can be tricked into believing that flat objects have depth and volume. This takes incredible amounts of computing in the visual cortex to perceive. In fact every second the visual cortex process upwards of 40 gigabytes to render sight as a perceivable sense. Some argue that 3D glasses and 3D media aggravate this problem by overloading the visual cortex. This is why some manufacturers have warnings stating that 3D media should only be used for short amounts of time, perhaps an hour or so a sitting. Some may notice that after a long time of viewing 3D media they get a headache, this may be due to the over use of the visual cortex as it is being taxed heavily with visual data.
Since 3D media as a major media source is fairly new more research must be conducted to get conclusive data on the threat that 3D glasses may pose to eyesight.
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