HEALTH




POLARIZED SUNGLASSES
More than just sunglasses
Courtesy Hobie Sunglasses



Most people have heard of the advantages of polarized 
lenses, but not all are aware of just what they are and how 
they work.

	Polarization is one of the fundamental properties of light 
waves.  It was discovered by 1808 by E.L. Malus, a 
French army engineer, who observed that light was polar-
ized by reflection.  When light strikes a surface like water, 
it becomes scattered and travels in all directions like a 
child's sparkler.  This is what is commonly known as 
glare.  Glare produces eyestrain and discomfort because 
the eye must work harder to overcome an in-crease in 
brightness while trying to view objects which appear 
washed-out.  Fishermen, for example, know the adva-
ntage of wearing polarized sunglasses.  They eliminate 
the water's glare, which allows them to see fish clearly 
beneath the surface.


	Regular sunglasses, regardless of the cost, are only 
coloured plastic or glass and cannot block out glare.   
These ordinary sunglasses just reduce the amount of 
visible light the eye sees, but the problem of glare still 
remains.

	A polarized lens, on the other hand, acts like a filter or 
lattice which only allows the useful light travelling from the 
object viewed to reach the eye, while blocking all the glare 
caused by the scattered light travelling in many different 
random directions.  Objects then appear sharper.  
Colours are seen more vividly and in true natural 
proportion, due to removal of most of the scattered white 
light.

	Unfortunately, many people still believe that the only 
polarized sunglasses available to them are the kind 
bought in drug stores.  The lenses used in these types of 
sunglasses are generally of poor quality and tend to 
distort vision which, at best, is annoying but is also 
potentially dangerous and fatiguing to the wearer.  Wrap-
around style sunglasses offer the most chance for 
distortion, especially at the corners where the lenses bend 
around the temples.  Low quality lenses can also contain 
vision-disrupting manufacturing defects such as bubbles, 
pits, scratches and streaks.

	Optical-quality lenses have true curves and are free of 
distortion and aberration.  This curvature, which is ground 
or moulded in and then polished, separates these high-
quality lenses from those most commonly found in 
sunglasses sold in regular retail stores.

	Polarized lenses are made by a special process which 
places an ultra-thin sheet of polarizing film within the lens 
itself.  This protects the film from any damage and allows 
the lens to be ground and polished.

	Polarizing lenses are particularly effective wherever 
there is reflected light.  This includes almost all outdoor 
activities whether it be around water, snow, sand or 
simply driving down the highway.


Barron Opticians, Kitchener
Dock 16, Oakville
Fogh Marine, Etobicoke
Muskoka Store, Bracebridge
The Chandelery, Ottawa
Waterline Sports, Toronto