The human body has the amazing ability to repair or replace damaged cells.  For instance, some of
the red blood cells in our body, that can live up to 120 days, are replaced on a routine basis at about
1% each and every day.  However, the lens of the eye does not have this capability.  The cells found
in the lens of the eye are never replaced.  The proteins of the lens, likewise, are never replaced.
While cells in other parts of our bodies can repair and replenish themselves, the lens can not repair
itself.  Injury and harm to the eyes merely accumulate over time leading to diminished eyesight. 
There are good reasons to wear polarized sunglasses to protect your eyesight.

One such damage to the eyes is cataracts. As the proteins of the lens gradually degrade, cataracts
form as a cloudiness to ones vision. This generally occurs when the lens is damaged over time from
ultraviolet (UV) light exposure.   

The back of the eye has a paper-thin lining called the retina.  The retina is responsible for capturing
the images we see and transferring it to our brain. One of the leading causes of blindness in the world
today is retinal disease. As we age the continual exposure to ultraviolet radiation causes damage to
our eyes that can not be reversed.   This accumulated damage to the retina is also called macular
degeneration. Many senior adults over the age of 65 have this malady.  Once your visual acuity is
damaged, even glasses can not correct your eyes.  Therefore prevention is critical to good vision.

When you are young you seem to always play out doors.  And probably without sunglass protection. 
That is why children are most susceptible to the harmful effects of UV exposure.  Although young
children may be most at risk for retinal damage, the accumulated injury to their eyes won’t manifest
itself until they are adults.  This is why all children should wear sunglasses throughout the day when
UV light is at its peak especially at the beach, while skiing or enjoying a day on the lake.  It has been
shown that children with dark colored eyes have some natural protection from the harmful effects of
the sun.  But that should not be an excuse to have them venture outdoors without proper eyewear. 
Vision has to last a lifetime.

Care should be taken when selecting the proper shades. Sunglasses need to block both UVA and
UVB radiation to be fully effective eye protection. While all sunglasses block UVB radiation, you
need eyewear to block at least 99% of UVA to be valuable sight protection.   Look for large lenses
that totally surround the eyes.  Polarized sunglasses add additional protection by eliminating harmful
glare which can interfere with our view.