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Who knew? Downward dog yoga position a potential eye danger
Head-down yoga positions cause a temporary and dramatic increase in intraocular pressure (IOP), but it's not yet known if that represents a risk to glaucoma patients.
In a study at the New York Eye and Ear Infirmary of Mount Sinai, head-down yoga positions increased IOP by as much as 12 mmHg. On the bright side, IOPs dropped back to normal within two minutes of subjects returning to a normal sitting position.
Other studies show a relationship between posture-induced IOP fluctuations and visual field loss in glaucoma patients, and some research shows that the headstand posture causes increased IOP, especially in glaucoma patients.
But there are several head-down positions in yoga. To study the effect of additional positions on IOP, lead author Jessica Jasien, a doctoral student, and colleagues enrolled 20 subjects, 10 with primary open-angle glaucoma (all had evidence of optic nerve head changes but were under good IOP control) and 10 healthy controls. Seventeen subjects were women; the glaucoma patients had a median age of 62, and the controls 36.
Each participant assumed the four common yoga poses of downward dog, forward fold, plow and waterfall, in that order, within an hour of each other for two minutes. IOP for both eyes was measured in a seated position prior to each pose, immediately at the start of the pose, two minutes into the pose, immediately after assuming a seated position and 10 minutes later, also seated.
In both groups, IOP increased significantly during all four yoga positions, with downward dog showing the highest increases: from a mean of 17 mmHg to 28 mmHg in the glaucoma patients, and from 17 mmHg to 29 mmHg in the controls.
In forward fold, IOP increased from 17 mmHg to 27 mmHg in the glaucoma patients, and from 18 mmHg to 26 mmHg in controls. During the plow, IOPs increased from 18 mmHg to 24 mmHg in the glaucoma patients and from 18 mmHg to 22 mmHg in controls. With the waterfall position, IOPs increased from 17 mmHg to 21 mmHg in the glaucoma patients and from 17 to 21 mmHg in the controls.
The IOP increases were not significantly different between glaucoma and normal subjects, but measurements were 2 mmHg higher on average in glaucoma patients.
Post written by Pippa Wysong
Fireworks: The Blinding Truth
Teen Blinded in One Eye By Fireworks
When Jameson Lamb and his friends began lighting fireworks one Fourth of July, it all seemed like harmless fun. Little did they know that at age 16 he would be robbed of his vision in one eye during a terrible accident.
They were at the family lake house in Michigan, where they bought a number of fireworks to set off near the lakeshore. After everyone went to bed, he and his friends snuck out to light a few more fireworks off over the lake. A Roman candle that they thought was extinguished shot out a round that hit him square in the eye. He ran screaming to the house and banged on the door. His mother let him in. The family drove to a hospital, his eye a black hole.
"It was black, full of debris," Lamb says.
Injuries like Lamb's are all too common. Fireworks caused 10,500 injuries last year, according to a 2015 Consumer Product Safety Commission report. Nearly half of the reported injuries occurred in people under 20 years old. The percentage of fireworks injuries that damage the eye area has increased to 20 percent, up from 16 percent the prior year.
Common fireworks eye injuries include burns and corneal abrasions (which can get infected and scar over, blocking vision) to more serious potentially blinding injuries such as retinal detachment and rupture of the eyeball. All can impede vision permanently.
A few interesting facts about our eyes
The eye is the second most complex organ in our body (after the brain).
It is composed of more than 2 million operational parts which can process 36,000 bits of information every hour!
Cornea is the only tissue in the eye that doesn't need blood
Cornea is essential for vision and the presence of blood vessels would have interfered in this process. So, this is the only living cell in our eye that is not directly connected with blood vessels. It gets oxygen and nutrients from the tear fluid in its outer part and the inside part gets nutrition from aqueous humour (the thick watery substance between the lens and the cornea).
All of us have a blind spot in our eyes.
Light enters the eye by passing through the pupil and hits the retina at the back of the eye. The retina is covered with light-sensing proteins. They send the information to the optic nerve which carries it back into the brain. The problem is, the optic nerve ends in the field of the retina itself. This creates a blind spot. The blind spots in each eye are aligned symmetrically so that most of the time, one eye's field of vision will compensate for the loss of vision in the other.
Your retinas actually perceive the outside world as upside-down – your brain flips the image for you.
If you want to see the world as your retinas do, try a pair of prism glasses. Just don't, you know, walk near sheer drops or operate heavy machinery while wearing them. In addition to being upside-down, images arrive at your retina split in half and distorted. Each half of your brain receives one half of the image, and then they scramble the images together to compose the whole picture you're used to seeing.
Your peripheral vision is very low-resolution and is almost in black-and-white.
You don't realise it because your eyes move to "fill in" the peripheral detail before you notice the difference.
The eyes require no rest
The eye is the only part of the human body that can function at 100% ability at any moment, day or night, without rest. But you should give rest to the eyelids and the external muscles of your eyes for its better functioning.
We blink 25000 times a day
Large number, isn't it? Blinking has two purposes – to keep the eyes lubricated and to protect the eye from foreign particles. Our eyelashes have short, curved, hair which serve as dust-catchers. The blinking reflex causes them automatically to lower, when exposed to harsh elements.
The amount of light entering the eye is constantly controlled
The central opening of your eye is known as the pupil. It changes size depending on the amount of light entering in the eye. The colored area around the pupil is called the iris which controls the size of the pupil. The colour of the iris, whether black, brown, blue or green is actually responsible for imparting the eye colour.
Is this real or science fiction?
Google has patented a new technology that would let the company inject a computerized lens directly into your eyeball. The technology is still in the works but this could become a reality sooner than we think! Read the full article on CNN Money.