Friday, February 25, 2011
By Mary Brophy Marcus, USA TODAY
Whether the increased sensitivity is harmless or hurtful to the brain is still up for debate, say researchers from the National Institutes of Health, who found that less than an hour of cellphone use is linked with increased activity in the part of the brain closest to the phone antenna.
It's not clear yet whether the radiation is potentially carcinogenic or has any other negative health implications — or positive ones, for that matter, says lead author Nora Volkow, director of the National Institute on Drug Abuse, about the research in this week'sJournal of the American Medical Association.
The year-long study on 47 people used positron emission tomography (PET) scans — a technique used to map out the brain. Study subjects underwent two injections with a dye that measures brain glucose metabolism, which is an indication of the brain's activity.
The first time around, cellphones were placed on both sides of the head. In half of the participants, the cellphone against the right ear was turned on with the sound muted for 50 minutes and in the other grooup, neither phone was activated. On the second test, the two groups were switched. None of the participants knew which phone was turned on.
The scientists found that metabolism in the brain region closest to the antenna — in the orbitofrontal cortex and temporal pole — was about 7% higher when the cellphone was on. The orbitofrontal cortex of the brain — one of the two areas that lit up on the scans — isn't linked to a single function, says Murali Doraiswamy, head of biological psychiatry at Duke Medical Center, who wasn't involved in the study. "It's broadly associated with emotion, sense of smell, memory, eating, aggression — a whole range of behaviors. It's like an orchestra conductor instead of just an individual musician with specific task."
The temporal area is critical to language and memory, says Keith Black, chairman of neurosurgery at Cedars-Sinai Medical Center in Los Angeles.
"This study raises a lot of questions," says Black, who was not involved in the study. "Will cellphones impact how we remember things, is there any relation to the risk of Alzheimer's? Will it affect our cognitive ability to manipulate language functions?"
Doraiswamy adds, "What would happen if you expose someone's head to a cellphone for three hours a day for six months or against other areas of the head?"
Black says he's concerned about children's increased use of cellphones, since their less developed skulls and brains are more susceptible to the radiation. And he worries about the impact of cellphone radiation over 10, 15, 20 years?
"The important thing to remember about a cellphone is that it's really a microwave radiation antennae. The amount of radiation you get from it is directly related to distance it is from the head," says Black, who recommends plugging in a headset, and says texting is probably OK, too.
On the flip side, "An increase in glucose metabolism doesn't mean it's dangerous," notes Doraiswamy. "Though cancer cells do have higher levels of glucose metabolism, it has also been associated in normal people (and in some animal studies) with some good things, including greater cognitive performance and greater blood flow."
Even so, Doraiswamy says he never uses his mobile phone close to his head. "I always put it on speaker phone."
Friday, February 18, 2011
by Matthew Humphries of Geek.com
If you wear eyeglasses then you know they can’t be perfect in all situations. You have a prescription that solves a problem such as long or short sightedness, but you still find yourself looking over the top of the glasses or having trouble focusing through them for certain viewing tasks.
PixelOptics has turned to technology in order to solve that problem, and claim to have produced some rather intelligent eyewear that automatically adjusts the prescription based on what you are trying to look at.
The new glasses are called emPower. They use a combination of a micro-accelerometer, chip, and small rechargeable battery embedded into the frame of the glasses. That setup controls an LCD layer which covers both lenses.
The accelerometer is used to tell when the wearer tilts their head forwards or backwards, and if in automatic mode, will adjust the lens output to suit. Tilting the head forwards suggests trying to read something so the lower reading area of each lens is activated. Tilt your head back up and the reading area is disabled giving the wearer a clear view in distance mode.
The switching between these modes only takes 7ms making it almost instant. Although a full-automatic mode exists, the wearer can swipe the touch-sensitive frame and switch to manual mode giving them more control.
As the reading area of prescription eyewear is only thought to be used 30-40% of the time, PixelOptics believe emPower will give wearers a much better experience as they don’t have to put up with blurry areas in their vision due to permanent reading areas. They are instead only there when you need them.
The emPower eyewear requires power and therefore ships with a charging cradle it can be placed in when not in use. A single charge is meant to give up to 3 days of use, though. They are also waterproof and have a transitions lens option for those who want them to double as sunglasses. When it comes to frames PixelOptics has turned to well-known eyewear company Aspex who will provide 48 frames in plastic, metal, or memory metal options.
emPower is expected to be available from April this year. As for price, nothing has been confirmed yet, but they will carry a premium of about 30% over the more typical prescription eyewear we buy putting them at around the $1,200 mark.
Wednesday, February 16, 2011
Thu, Feb 03, 2011
Looking people straight in the eye may or may not reveal their honesty -- but the eyes *can* tell you about cholesterol, liver disease, or diabetes, if you know what to look for.
"The eye is a unique window into health," says ophthalmologist Andrew Iwach, spokesperson for the American Academy of Ophthalmology (AAO) and executive director of the Glaucoma Center of San Francisco. "It's the only place in the body where, without surgery, we can look in and see veins, arteries, and a nerve (the optic nerve)."
The eyes' transparency explains why common eye diseases such as glaucoma, cataracts, and macular degeneration can be detected early with regular eye exams.
"Unfortunately, people get busy and delay not only eye exams but regular physicals. That's why eye doctors sometimes discover other issues, like diabetes or high blood pressure," Iwach says. Especially vulnerable, he says: People like caregivers, who worry about others around them while neglecting care for themselves.
Keep your eye out for these 14 problems.
1. Red flag: Disappearing eyebrows
What it means: Shaved eyebrows are a fad (or fashion, if you will) in some circles. But when the outer third of the brow (the part closest to the ears) starts to disappear on its own, this is a common sign of thyroid disease -- either hyperthyroidism (overactive thyroid gland) or hypothyroidism (underactive thyroid gland). The thyroid is a small but critical gland that helps regulate metabolism, and thyroid hormones are among those critical to hair production.
More clues: Brows tend to thin with age naturally. But with thyroid disease, the brow-hair loss isn't evenly distributed; it's a selective dropout on the ends. There's usually a loss of hair elsewhere on the body, too, but the brows are so prominent, it's often noticed here first. Early graying is a related sign of a thyroid problem. Women are more often affected than men, and hyperthyroidism especially strikes women in their 20s and 30s.
What to do: Mention this symptom to a dermatologist or your regular doctor. Most other symptoms of both hyper- and hypothyroidism are notoriously broad and general. Before you see a doctor, make note of any other changes you've noticed, possibly concerning weight, energy levels, bowel or menstrual regularity, mood, or skin changes.
2. Red flag: A stye that won't go away
What it means: The vast majority of the time, a small, raised, often reddish bump along the inner or outer eyelid margin is just an unsightly but innocuous stye (also called a "chalazion"). But if the spot doesn't clear up in three months, or seems to keep recurring in the same location, it can also be a rare cancer (sebaceous gland carcinoma).
More clues: Actual styes are plugged-up oil glands at the eyelash follicle. Fairly common, they tend to clear up within a month. A cancerous cyst that mimics a stye, on the other hand, doesn't go away. (Or it may seem to go away but return in the same spot.) Another eyelid cancer warning sign: Loss of some of the eyelashes around the stye.
What to do: Point out a persistent stye to an ophthalmologist (a medical doctor who specializes in the eye). A biopsy can confirm the diagnosis. The stye is usually removed surgically.
3. Red flag: Bumpy yellowish patches on the eyelid
What it means: Xanthelasma palpebra, the medical name for these tiny yellow bumps, are usually a warning that you may have high cholesterol. They're also called "cholesterol bumps" -- they're basically fatty deposits.
More clues: Sometimes people mistake these bumps for a stye, but with xanthelasma, there tends to be more than one bump and they're quite small.
What to do: See your doctor or a skin or eye specialist. A diagnosis can usually be made by sight. An ophthalmologist can also examine the eye and see deposits; for this reason, in fact, sometimes high cholesterol is first diagnosed during a routine eye exam. The problem usually isn't serious and doesn't cause pain or vision problems. A physician will also evaluate you for other signs of coronary artery disease.
4. Red flag: Burning eyes, blurry vision while using a computer
What it means: You might be a workaholic, and you definitely have "computer vision syndrome" (CVS). The eyestrain is partly caused by the lack of contrast on a computer screen (compared with ink on paper) and the extra work involved in focusing on pixels of light. What's more, by midlife the eyes lose some of their ability to produce lubricating tears. Irritation sets in, adding to blurriness and discomfort.
More clues: Does the problem worsen in the afternoon (when the eyes tend to become drier)? Is it worse when you're reading fine print (more eyestrain)? People who wear glasses or contacts tend to be bothered more by CVS. "Sometimes the problem is made worse by a fan positioned so it blows right in the face," the AAO's Iwach adds, noting that the air further dries tired eyes.
What to do: Reduce glare by closing window shades, investing in a computer hood, or checking out antireflective coating for your glasses (if you wear them). Simply tinkering with the contrast of your screen can help, too. White areas should neither glow brightly like a light source nor appear gray. Flat-panel LCD display screens (like those on laptops) cause less eyestrain than older models. Keep reference material close to the same height as your monitor, giving your eyes a break from having to refocus so much.
5. Red flag: Increasing gunk in the eye
What it means: Blepharitis -- inflammation of the eyelids, especially at the edges -- can have several causes. Two of them, surprisingly, are conditions better associated with other body parts: scalp dandruff and acne rosacea (which causes flushed red skin, usually in the faces of fair-skinned women at midlife).
More clues: The eyes may also feel irritated, as if specks have gotten in them. They may burn, tear, or feel dry. The crusty debris tends to gather in the lashes or the inner corners of the eyes, or even on the lids.
What to do: With clean hands, apply a warm, damp washcloth to the eyes for about five minutes at a time to loosen debris and soothe the skin. See a doctor, who may prescribe an antibiotic ointment or oral antibiotics, as well as artificial tears.
6. Red flag: A small blind spot in your vision, with shimmering lights or a wavy line
What it means: An ocular migraine (also called an "ophthalmic migraine," "optical migraine," or "migraine aura") produces this disturbed vision, with or without an accompanying headache. Changes in blood flow to the brain are thought to be the cause.
More clues: The visual distortion starts in the center of the field of vision. It might appear as a bright dot, dots, or a line that can seem to move and disrupt your ability to see properly, as if you were looking through a pocked or cracked window. It's painless and causes no lasting damage. Individuals seem to have different triggers (ranging from chocolate, caffeine, and alcohol to stress). A headache, possibly severe enough to cause nausea, sometimes follows.
What to do: If you're driving, pull over until the phenomenon passes (usually within an hour). Do have an eye specialist check it out if vision impairment lasts more than an hour or so, to rule out serious problems such as a retinal tear; or if you also experience other symptoms elsewhere that could indicate stroke or seizure (such as fever, loss of muscle strength, or speech impairment).
7. Red flag: Red, itchy eyes
What it means: Many things can irritate eyes, but itchiness accompanied by sneezing, coughing, sinus congestion, and/or a runny nose, usually screams "I'm allergic!" When the eyes are involved, the trigger is usually airborne, like pollen, dust, or animal dander.
More clues: An eye allergy can also be caused by certain cosmetics or ointments. Some people, for example, are allergic to the preservative in eye drops used to treat dry eyes.
What to do: Staying away from the allergic trigger is the usual treatment. Antihistamines can treat the itchiness; those in eye-drop or gel form deliver relief to the eyes faster. If the problem turns out to be an allergy to eye drops, look for a preservative-free brand.
8. Red flag: Whites of the eye turned yellowish
What it means: Two groups of people most often show this symptom, known as jaundice: Newborns with immature liver function and adults with problems of the liver, gallbladder, or bile ducts, including hepatitis and cirrhosis. The yellow in the white part of the eye (the sclera) is caused by a buildup of bilirubin, the by-product of old red blood cells the liver can't process.
More clues: "Other tissues of the body would have the same look, but we can't see it as clearly as in the whites of the eye," says ophthalmologist Iwach. (Skin can also turn yellowish when a person consumes too much beta carotene -- found in carrots -- but in those cases the whites of the eyes remain white.)
What to do: Mention the symptom to a doctor if the person isn't already under care for a liver-related disease, so the jaundice can be evaluated and the underlying cause treated.
9. Red flag: A bump or brown spot on the eyelid
What it means: Even people who are vigilant about checking their skin may overlook the eyelid as a spot where skin cancer can strike. Most malignant eyelid tumors are basal cell carcinoma. When such a tumor appears as a brown spot, then -- as with any other form of skin cancer -- it's more likely to be malignant melanoma.
More clues: Elderly, fair-skinned people are at highest risk. Look especially at the lower eyelid. The bump may look pearly, with tiny blood vessels. If the bump is in the eyelash area, some eyelashes may be missing.
What to do: Always have any suspicious skin spots or sores checked out by a dermatologist, family physician, or eye doctor. Early detection is critical, before the problem spreads to nearby lymph nodes.
10. Red flag: Eyes that seem to bulge
What it means: The most common cause of protruding eyes is hyperthyroidism (overactivity of the thyroid gland), especially the form known as Graves' disease. (First Lady Barbara Bush had it.)
More clues: One way to tell if an eye is bulging is to see whether there's any visible white part between the top of the iris and the upper eyelid, because normally there shouldn't be. (Some people inherit a tendency toward eyes that bulge, so if the appearance seems to run in a family, it probably isn't hyperthyroidism.) The person may not blink often and may seem to be staring at you. Because the condition develops slowly, it's sometimes first noticed in photos or by the occasional visitor rather than by someone who lives with the person every day.
What to do: Mention the symptom to a doctor, especially if it's present in tandem with other signs of Graves' disease, including blurry vision, restlessness, fatigue, increase in appetite, weight loss, tremors, and palpitations. A blood test can measure thyroid levels. Treatment includes medication and surgery.
11. Red flag: Sudden double vision, dim vision, or loss of vision
What it means: These are the visual warning signs of stroke.
More clues: The other signs of stroke include sudden numbness or weakness of the arm or leg or face, typically on just one side of the body; trouble walking because of dizziness or loss of balance or coordination; slurred speech; or bad headache. In a large stroke (caused by a blood clot or bleeding in the brain), these symptoms happen all at once. In a smaller stroke caused by narrowed arteries, they can occur across a longer period of minutes or hours.
What to do: Seek immediate medical help by calling 911.
12. Red flag: Dry eyes that are sensitive to light
What it means: Sjogren's (pronounced "show-grins") syndrome is an immune system disorder. It impairs the glands in the eyes and mouth that keep them moist.
More clues: Sjogren's usually affects women over age 40 with autoimmune disorders such as rheumatoid arthritis or lupus. Usually the eyes and mouth are affected together. The person may also have vaginal dryness, dry sinuses, and dry skin. Because of a lack of saliva, it can be difficult to chew and swallow.
What to do: A doctor can diagnose Sjogren's through testing. Artificial lubricants (such as artificial tears) are usually necessary to protect the eyes, as well as to improve eating. Drinking plenty of water also helps.
13. Red flag: Sudden difficulty closing one eye, inability to control tears in it
What it means: Bell's palsy is an impairment of the nerve that controls facial muscles (the seventh cranial nerve), causing temporary paralysis in half the face. It sometimes follows a viral infection (such as shingles, mono, or HIV) or a bacterial infection (such as Lyme disease). Diabetics and pregnant women are also at higher risk.
More clues: Half of the entire face, not just the eye, is affected. Effects vary from person to person, but the overall effect is for the face to appear droopy and be weak. The eyelid may droop and be difficult or impossible to close, and there will be either excessive tearing or an inability to produce tears. The effects tend to come on suddenly.
What to do: See a doctor. Most cases are temporary and the person recovers completely within weeks. Rarely, the condition can recur. Physical therapy helps restore speaking, smiling, and other tasks that require the facial muscles working in unison, and it also helps avoid an asymmetrical appearance. Professional eye care can keep the affected eye lubricated and undamaged.
14. Red flag: Blurred vision in a diabetic
What it means: Diabetics are at increased risk for several eye problems, including glaucoma and cataracts. But the most common threat to vision is diabetic retinopathy, in which the diabetes affects the circulatory system of the eye. It's the leading cause of blindness in American adults.
More clues: The changes linked to diabetic retinopathy tend to show up in people who have had the disease for a long time, not those recently diagnosed. The person may also see "floaters," tiny dark specks in the field of vision. Sometimes diabetes causes small hemorrhages (bleeding) that are visible in the eye. There's no pain. People with poorly controlled blood sugar may have worse symptoms.
What to do: Someone with diabetes should have a dilated eye exam annually to catch and control the earliest stages of retinopathy, glaucoma, cataracts, or other changes -- before they manifest as changes you're aware of.
Friday, February 11, 2011
By Jennifer Goldberg
Moira Saganski's computer gives her a headache every day—and it's not from the amount of e-mails in her inbox. The 54-year-old chief financial officer from Toronto suffers from computer vision syndrome, a condition that's becoming increasingly common among middle-aged women who spend a lot of time looking at computer screens.
"Computer vision syndrome [C.V.S.] describes eye and vision symptoms that are associated with digital screens, including computers, Blackberrys and televisions," says Dr. Mira Acs, an optometrist based in Toronto. "We're seeing a higher volume of baby boomers complaining of eye strains and fatigue, and C.V.S. has become more frequent over the past five years as technologies have evolved. We all stare at screens of all kinds for long periods of time."
A recent study by Leger Marketing found that baby boomer women are spending more time in front of computer screens than ever before—more than four hours a day, on average—and 43 percent of them suffer from ailments related to screen-viewing.
Saganski spends anywhere from six to 13 hours working on a computer every day, and it's taking a toll on her vision. "I first realized that my eyes were getting blurry and very achey," she recalls. "My vision was changing and I had a lot of headaches that were related to strain on the eye."
Those are the symptoms of C.V.S., says Acs, as are light sensitivity and dry eyes. However, as these ailments are often associated with general fatigue, she says that many people don't even notice they have a problem. But left untreated, these symptoms could persist and even worsen.
"Sometimes [C.V.S.] requires vision correction," says Acs. "You may need to have your glasses or contact lenses fit for how you use a computer." An optometrist may recommend computer glasses, which have a different prescription on the top part of the lenses that allows you to focus on a computer screen. You may also get a prescription for artificial tears to relieve dry eyes.
Saganski says that after being diagnosed with C.V.S., she has become more aware of how her computer affects her vision, and what she can do for the uncomfortable symptoms. "Because I'm aware of it, I do try to take a break [when using a computer]. I go totally out of my office and take a walk around the work stations," she says.
Here are some steps you can take to help protect your eyes from computer-induced strain:
Saganski is certainly on the right track with her short office walks: When working on a computer, the Canadian Association of Optometrists recommends following what they call the "20-20-20 rule": Take a 20-second break from using your computer every 20 minutes and focus your eyes on something at least 20 feet away. This gives your eyes a chance to rest and recover from strain.
Adjust your screen
Be screen smart, says Acs. "Take a few minutes to adjust the brightness and contrast of your screen, and make sure it's positioned correctly—about arm's length [about 50 cm] from your eyes." The screen should also be places at 20 degrees below eye level.
Get the right light
"The lighting in the room is also very important," says Acs. Unfortunately, not everyone has the freedom to adjust the lights in their work environment, but you can cut glare and reflections on your home computer by diffusing the light that hits the screen. This will help reduce the amount of squinting you do.
Visit the eye doctor
Make regular appointments with your optometrist to ensure that you're wearing the appropriate corrective eyewear. You also want to make sure that what seems like C.V.S. symptoms aren't the result of another vision problem.
Web exclusive: October 2009
Saturday, February 5, 2011
My video presentations are now appearing on You Tube. I have answered questions on Cataracts, Macular Degeneration, Children's Vision and Ultraviolet Protection.
Here are the links:
Ultraviolet Rays and the Eye
Thursday, February 3, 2011
By Fiona Macrae and Claire Bates
Last updated at 4:32 PM on 5th November 2010
A 46-year-old man thought he would never see again after a devastating eye disease robbed him of his sight.
Yet these amazing pictures show the moment Miikka Terho was able to identify a banana placed before him and spell out his name after he was fitted with a revolutionary microchip.
The implant is placed at the back of the eye allowing men and women who thought they would never be able to see again to read the hands of a clock and identify everyday objects.
One man saw his girlfriend’s smile for the first time, while another was able to read his own name.
It is thought the device could even work in certain cases of blindness from birth.
Video footage released by the Royal Society shows patient Mr Terho from Finland studying an apple and a banana.
'This one on the right looks longer and is curving,' he told scientists looking on.
'It could be a banana,' he adds, causing the team to break out in spontaneous applause.
The results have been described as ‘quite astonishing’ by eye surgeons and the first Britons could be benefiting within months.
Experts say the sub-retinal implant could revolutionise the treatment of blindness in the same way as cochlear implants have transformed the life of the deaf.
First to benefit will be people with retinitis pigmentosa, a hereditary disease that gradually destroys the light-sensitive retina at the back of the eye leading to total blindness.
But in time, the bionic eye could also be used to treat age-related macular degeneration, the most common cause of blindness in the elderly, which has no cure and affects some 500,000 Britons.
Robert MacLaren, an Oxford University professor of ophthalmology, said: ‘Now when I discuss eye disease with patients, I can, at least in some cases, hold out some hope. For a patient, it will make it easier to deal with the somewhat appalling prognosis that they are going to lose their sight.’
The device, the brainchild of German firm Retina Implant AG, consists of a very thin microchip, just 3mm by 3mm in size and packed with 1,500 light sensors designed to replace those in the retina lost to disease.
Although bionic eyes have been piloted before, this battery-powered implant is the first not to require cumbersome accessories such as a camera mounted on dark glasses.
Today, a prestigious journal, Proceedings of the Royal Society B, describes how the implant allowed two blind men and a woman to see shapes and objects for the first time since losing their sight to retinitis pigmentosa.
Within days, all three could visually locate objects placed on a table, including a cup and saucer. Several more have been treated since.
Researcher Dr Eberhart Zrenner, founder of Retina Implants, said: ‘One young patient told me how he looked at his girlfriend and saw her smiling. Another patient was sitting in her garden and suddenly discovered a sunflower outlined against the sky.
‘One saw bugs moving across the grass. Another looked up at the sky and saw the white line left by an aeroplane. It gives them back not only mobility but also pleasure.'
Professor MacLaren, who plans to start testing the device in Britain early next year, described the results as ‘quite astonishing’. The consultant eye surgeon said: ‘Up until now, this concept would have been considered only in the realms of science fiction.
‘The level of vision is rudimentary, but we’re talking about making someone who is completely blind see well enough to walk around without a guide dog.’
The device is expected to cost £20,000 to £45,000, on a par with training a guide dog.
However, it does not work in all cases and much more work is needed before it becomes widely available, perhaps within five years. Professor MacLaren said: ‘There are still many questions, such as how long the chip will last and how it might be improved.
‘There is little doubt though that this research will progress rapidly.’