June 30, 2010
LOS ANGELES — A dangerous drinking fad known as “Vodka eyeballing” is growing in popularity on college campuses in the UK and the United States, and experts say it could leave students blind.
So-called “eyeballers” claim it’s an instant high with a splash of alcohol giving them a buzz, literally, in the blink of an eye.
But, doctors say, it’s a dangerous trend that could cause permanent vision damage.
The American Academy of Ophthalmology issued the following statement:
A dangerous drinking game called “vodka eyeballing” is attracting public attention on YouTube. People need to be aware that anyone who pours vodka directly into his eye risks damaging the surface epithelial cells–often causing pain and infection. More seriously, ”eyeballing” can also lead to permanent vision damage by killing endothelial cells in deeper layers of the eye’s cornea. This is unlikely, but possible. The cornea is the clear outer part of the eye that focuses light and provides much of the optical power. Depending on the amount of alcohol and length of time it is in contact with the eye, epithelial cell loss could result in corneal ulcers or scarring, not to mention a great deal of pain. And if endothelial cells die off, vision recovery would be uncertain.
“Eyeballers” do not even get a “quick high” as claimed, because the volume of vodka absorbed by the conjunctiva and cornea is too small to have that effect.
The American Academy of Ophthalmology strongly advises the public not to engage in “vodka eyeballing.”
June 30, 2010
* Pilot shot by Taliban
* Still lands helicopter
* Saves all 20 aboard
June 29, 2010
A tribe of water nomads, the Mokens, living in Myanmar and Thailand are able to see clearly underwater! The Moken tribe harvests tiny brown clams, etc. from the ocean floor from among brown stones without the aid of goggles.
Studies revealed that the Moken children’s vision is similar to European children’s vision on land but twice as clear underwater; the eye structure between the two groups is similar. The clear vision is attributed to the ability of the Moken children to voluntarily control accommodation while diving, effectively making up for some of the lost corneal power. It is believed, through preliminary studies, that this is ability is trainable.
Also, Moken children also constrict their pupils more (to 1.96 mm) than European children constrict (only to 2.5 mm) which may contribute to the sharper underwater vision. This is the same idea as using a smaller aperture on a camera to obtain a sharper image.
June 28, 2010
Sir Harold Ridley, who was an ophthalmic surgeon in London, found that pilots came back from their missions with little pieces of perspex in their eye (shattered screens of the planes they were flying in), to which the eye did not seem to “object”: no inflammation of any significance was found in their eye. This material was modified and further developed into artificial lenses that are used in cataract operations today.
June 28, 2010
Onions contain a high amount of sulfur compounds. When you slice them, it causes cells to break apart and the release of alliinase, a particular enzyme unique to onions (and garlic plants). This enzyme reacts with sulfoxide amino acids to generate sulfenic acid, however this compound is highly unstable and will breakdown into propanethial-S oxide, a gas compound which then is dispersed into the immediate environment.
This gas wafts up slowly towards your eyes while you prepare the onions and upon contact with the tear film layer of your cornea, it reacts to produce a dilute solution of sulfuric acid. Acid in your eyes = burning and stinging = crying.
In order to avoid the propanethial-S oxide compound from forming, you can force the gas to be formed into the sulfuric acid before dispersing by providing ample amounts of water while you slice the onion (ie. under a tap of running water, or in a basin). Or you may choose to change the enzyme kinetics by freezing or chilling the onion to disable the alliinase and prevent the propanethial-S oxide from ever forming.
June 28, 2010
Iris recognition is a method used to verify a person’s identity, kind of like a fingerprint. Iris recognition has been featured in movies like Demolition Man, Minority Report and Angles and Demons , but did you know that researchers have developed the technology and that it is actually in use today?
Briefly, iris recognition is a process by which a photograph is taken of a person’s eye and the structure of the iris is compared pixel by pixel with an image on file. Matches have been shown to be extremely accurate using this technique.
Iris recognition is currently in use in several international airports for immigration purposes and also for “passwords” to log into a computer.
Scientists hope to use this technology for many things in the future including forensic and police applications as well as for entry into buildings and automobile ignitions!