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Finally, these are the secret to find that perfect frame to match your face shape.
OVAL SHAPE
Characteristics:
Well-proportioned, symmetrical, jaw tapers evenly to chin.
Most Complementary Style:
You're lucky. Generally any type of sunglasses look great, just make sure that the size of the frame is proportionate to the face. Try larger styles, wrap-arounds and aviators.
SQUARE SHAPE
Characteristics:
Horizaontal width of face is same at forehead and across cheekbones, heavy jaw line.
Most Complementary Style:
Select frames that are not as wide as the widest part of the face to minimize width and add length. Choose fluid or round styles.
TRIANGULAR SHAPE
Characteristics:
Widest horizontally at forehead, narrower at cheekbones, even narrower at chin, cheeks and ears.
Most Complementary Style:
Select frames that balance the face and broaden the lower part of your face. Low temples, styles that are wider on the bottom and rimless styles are good.
ROUND SHAPE
Characteristics:
Full-looking face with round chin and hairline. Widest point at cheeks and ears.
Most Complementary Style:
Select frames with straight or angular lines to sharpen and help make the face look thinner and longer.
RECTANGLE SHAPE
Characteristics:
Long and slender, may have narrow chin or high forehead.
Most Complementary Style:
Select frames that will both shorten and widen the face at the same time. Round or deep silhouettes help soften the face.
Which lenses are the best choice for healthy sight:
Regular clear lenses or Transitions lenses?
HEALTHY SIGHT. IT'S MORE THAN JUST SEEING 20/20.
If you think all you can expect from corrective lenses is better vision, you should know more about Transitiions lenses.
That's because Transitions lenses can help protrect your eyes from glare and the harmful effects of UV rays while they're also doing their primary job: improving your eyesight.
Transitions lenses: the ideal choice for healthy sight: Transitions lenses give you so many benefits you need for healthy sight, including:
* Convenient protection from UV rays.
* Visual quality indoors and out.
* Greater comfort and relief from eyestrain and fatigue.
Your eyes need sun block as much as your skin.
The UV rays that can burn your skin or cause skin cancer can also cause long-term damage to your eyes. And this may lead to seious conditions like cataracts or macular degeneration.
But Transitions lenses block 100% of UVA and UVB rays to help protect your eyes and preserve your sight.
ESSENTIAL BENEFITS OF TRANSITION LENSES
* Block 100% of UVA and UVB radiation.
* Darken quickly outdoors (7th generation technology)
* Fade back indoors.
* Reduce eye fatique and eye strain associated with glare.
THE eyes may be the windows to the soul, but they also make pretty good peepholes into the brain. Thanks to an optical version of ultrasound, it is becoming possible to locate and monitor the growth of brain tumours, and to track neurodegenerative conditions like multiple sclerosis, Alzheimer's and Parkinson's disease - all by peering into the eye.
The brain is connected to each eye by an optic nerve, so any degeneration of the brain caused by such diseases can also damage cells along the nerve and in the retina, says Helen Danesh-Meyer, an eye surgeon and neuro-ophthalmologist at the University of Auckland Medical School in New Zealand. Indeed, a loss of visual function is one of the first symptoms in many people with a neurodegenerative condition.
Although evidence of a link between degeneration of the optic nerve and diseases such as Alzheimer's has been around since the late 1980s, without instruments capable of measuring the retinal changes accurately it is only recently that this knowledge could be put to use, says Danesh-Meyer.
The accuracy of ophthalmological tools has greatly improved in the last few years. Developments include a type of laser-camera technique called Heidelberg retina tomography (HRT), and a laser device called GDx, both of which can be used to scan the shape and thickness of optical nerve fibres at the back of the eye.
Both tools are now widely used to manage glaucoma, but in 2006 Danesh-Meyer became one of the first researchers to use them to study neurodegenerative diseases by looking at the region of the retina where ganglion cells meet to form the optic nerve - a region known as the optic nerve disc (OND). In a trial involving 40 Alzheimer's patients and 50 healthy volunteers, she was able to show that people with Alzheimer's had a distinctive enlargement to a cup-shaped part of their OND and a progressive thinning of the retinal nerve fibres within the disc.
People with Alzheimer's have a distinctive shape to the disc of their optic nerve.
Following this discovery, researchers have been using even more accurate instruments to track degenerative changes in the OND to monitor the progression of diseases like Alzheimer's, Parkinson's and MS. But it has been the emergence of optical coherence tomography (OCT) that appears most promising: it became commercially available in 2006 and is fast becoming a standard tool for the management of glaucoma and diabetic retinopathy. When applied to the OND, it produces highly detailed two and three-dimensional images of the subsurface retinal tissue, says Denise Valenti at Boston University, who has been using OCT to study Parkinson's and Alzheimer's.
The technique works very much like ultrasound, but bounces light off the tissue instead of sound waves. One beam of light is fired at the tissue and another at a reference mirror. When the reflected beams have travelled an identical distance, interference will make their combined beam brighter than if the distances are different. So by reflecting one beam off of different layers of tissue, and moving the reference mirror until the combined reflected beam is brightest, the technique can measure the depths of each section of tissue and build up a detailed image of its structure. It has proved particularly useful in ophthalmology because the semi-transparent nature of retinal tissue makes it possible for OCT to penetrate to greater depths - up to several millimetres. When applied to the OND it can give information about both the shape and thickness of retinal nerve fibres, allowing even subtle changes to be tracked.
Such changes can be used to monitor the progression of diseases non-invasively and relatively cheaply. Unlike MRI, which is expensive and can require patients to remain still for an hour or more, OCT is increasingly available in clinics and can be carried out in a few minutes. "It's extremely inexpensive compared to other tests," says Valenti.
One possibility is to use OCT to monitor the effectiveness of treatments for neurodegenerative diseases, says Danesh-Meyer: "These drugs can have a lot of side effects, so if they are not having a benefit then you won't want to continue with them."
Laura Balcer, a neurologist at the University of Pennsylvania School of Medicine in Philadelphia, has been using OCT on patients taking part in MS drug trials to try to establish if the system can accurately gauge drug efficacy. Such an objective tool would allow symptoms to be picked up that might otherwise go unreported, she says. For example, OCT has already shown that even in people with MS whose eye function is normal, there are marked differences in OND shape and fibre thickness compared with healthy people. "MS researchers are very excited about OCT," she says.
The technology is also proving its value as a tool for monitoring brain tumours, which can affect vision by pressing on the optic nerve. Such pressure will cause damage to different parts of the OND, depending on where in the brain the tumour is located, says Danesh-Meyer. What's more, the extent of the thinning of the nerve-disc fibre can also reveal whether vision will be restored upon removal of the tumour.
In the case of one patient who was 24 weeks pregnant following several IVF attempts, OCT monitoring allowed surgeons to hold off on removing her brain tumour until well into the third trimester, when the fetus had a better chance of survival. The usual treatment would have been to operate immediately to prevent permanent vision loss, but this would have risked inducing premature labour. By monitoring the compression on the optic nerve to ensure it did not reach the point at which permanent damage was inevitable, Danesh-Meyer was able to keep tabs on the tumour's growth and delay the surgery. As a result, the baby was born safely and the patient kept her vision.
The ultimate aim for many using OCT is to diagnose diseases before symptoms arise. The difficulty with this is that the thickness of retinal nerve fibres can vary from person to person, says Danesh-Meyer, so there is not always a clear baseline from which to compare patient scans.
Eventually though, the low cost and simplicity of the technology may make it feasible for people to be given an OCT scan of each eye at a young age, to give doctors a record of their healthy retinal nerve, says Danesh-Meyer. With regular screening, some neurological conditions could be spotted incredibly early.
"We're really just at the cusp of knowing where this is all going."
*Information is provided by 'New Scientist' magazine issued on 17 January 2009 by Duncan Graham-Rowe.
The Issue
It is important to protect your eyes against damage from the sun. For most people, an inexpensive pair of sunglasses will do the job.
Background
The sun produces many different kinds of light. The kinds most likely to injure the eye are:
* ultraviolet radiation, which is invisible and is often called "UV rays";
* bright or intense light; and
* blue light.
About UV Light and Blue Light
UV rays carry more energy than visible light rays, so the eye is at greater risk of damage from absorbing UV radiation than from absorbing other kinds of light. There are two types of UV rays that reach the Earth's surface: UVA and UVB. These rays can cause, or speed up the progress of several diseases that affect the eye or its supporting structures. UVB rays have also been linked to skin cancer. Most of the damage caused to eyes by UVB and UVA rays happens over a long period of time and cannot be reversed. Sensitivity to ultraviolet radiation varies from one person to the next.
Blue light is visible light in the blue portion of the colour spectrum. The intense glare of light reflecting off snow or water contains blue light. Your eyes cannot focus clearly in blue light. Some scientists believe that routine exposure to blue light over many years may age the retina and increase the risk of blindness in some people over the age of sixty.
How Light Can Damage Eyes
All light is a form of energy. When your eyes absorb light, the process creates heat or chemical reactions in eye tissue. These reactions can cause permanent damage if the eye's natural ability to heal itself is overwhelmed.
Different parts of the eye absorb different kinds of UV radiation and light. For example:
* The surface layers of the outer part of the eyeball (the cornea and the conjunctiva) absorb UVB rays.
* The lens absorbs mainly UVA rays.
* The retina (the light-sensitive lining at the back of the inner eyeball) absorbs visible light.
If eyes are overexposed to ultraviolet radiation, the front portion of the eyes may be damaged. If visible light is too bright or intense, or if you stare directly at the sun, even briefly, the retina can be damaged, causing permanent loss of vision.
UV radiation, along with wind and drying of the eye, may cause snow blindness, an uncomfortable but temporary condition. There is some evidence that daily exposure to UV radiation in very bright sunlight over many years may increase the risk of developing cataracts. Cataracts cause a gradual clouding of the natural lens of the eye.
Choosing Sunglasses
Make sure the lenses are dark enough to keep your eyes comfortable, but not so dark that they reduce your vision. If you spend a lot of time outdoors in intense glare from sunlight bouncing off snow or water, you should wear sunglasses that block blue light. Medium to dark lenses with a grey, or a slightly brown or green tint, will filter out most blue light.
Most sunglasses have plastic lenses. These lenses are tougher than glass and less likely to shatter. If you buy plastic lenses, look for a pair with a scratch-resistant coating. Check the lenses for distortion by putting the sunglasses on and looking at a rectangular pattern, such as floor tiles. If the lines stay straight when you move your head up and down, and side-to-side, then the amount of distortion is acceptable.
Sunglasses are made with different kinds of lenses to meet different needs:
* Regular lenses reduce the brightness of everything evenly.
* Polarizing lenses are designed to cut glare due to reflection. This means they are good for driving and outdoor activities in the snow or on water.
* Photochromic lenses change with the intensity of UV light by turning darker when outdoors and lighter when indoors. If you wear these for driving, choose sunglasses that are fairly dark.
* "Flash" or mirror lenses reflect all or part of the light instead of absorbing it. They offer no performance advantage as they scratch easily. You should choose a pair with a scratch-resistant coating.
Standards for UV Protection
You cannot tell how much UV protection a pair of sunglasses will provide by their price, colour, or by the darkness of the lenses. Look for a label that lists the type and amount of protection. Manufacturers follow voluntary industry standards when labelling these products. Sunglasses that comply with industry standards are grouped in three categories:
* Cosmetic sunglasses have lightly tinted lenses for use in sunlight that is not harsh. They block from 0 to 60 percent of visible light and UVA rays, and between 87.5 and 95 percent of UVB rays. These glasses are not usually recommended for daylight driving.
* General purpose sunglasses block from 60 to 92 percent of visible light and UVA rays, and between 95 and 99 percent of UVB rays. These sunglasses are good for driving, and are recommended whenever sunlight is harsh enough to make you squint.
* Special purpose sunglasses block up to 97 percent of visible light and up to 98.5 percent of UVA rays. They also block at least 99 percent of UVB rays, and are suitable for prolonged sun exposure. These sunglasses are not recommended for driving.
Minimizing Your Risk
Wearing sunglasses makes sense. Properly chosen sunglasses will protect your eyes against damage from UV rays, bright light, and blue light. There are also other safety factors to consider. For example, if you are driving a vehicle in bright sunlight, it is safer to wear sunglasses, because they reduce glare and improve contrast.
You can also help protect your eyes by wearing a wide-brimmed hat or visor when you are out in bright sunlight, and by avoiding exposure to bright sunlight, especially in the summer between 11:00 a.m. and 4:00 p.m., when the sun's rays are strongest.
This information is brought to you by Health Canada
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