Tag Archive for: UV rays

All Sunglasses Are Not Created EqualThe sun produces many different kinds of light, and the most likely to injure your eyes are ultraviolet,  called “UV rays“.   When eyes are overexposed to ultraviolet radiation, the front portion of the eyes may become damaged.

When your eyes absorb light, the process creates heat or chemical reactions in the eye tissue. These reactions can cause permanent damage if the eye’s natural ability to heal itself is overwhelmed.  Properly chosen sunglasses will protect your eyes against damage from UV rays.

Make sure your lenses are dark enough to keep your eyes comfortable, and  that you wear your sunglasses every time you go outside. Just like wearing sun screen, a hat and staying hydrated, wearing your sunglasses should be part of your sun healthy lifestyle.

You can’t tell how much UV protection a pair of sunglasses will provide by their price, colour, or the darkness of the lenses. Instead, look for a label that lists the type and amount of protection.

Different lens tints filter out different wavelengths of light, so choose your tint based on need:

• Green—Allows true color perception and good contrast in bright light; reduces eyestrain in bright light.

• Gray—Allows true color perception, but does not enhance contrast; good for cycling or running.

• Brown—Good in hazy sun, enhances contrast; good for high-glare environments.

• Amber—Brightens cloudy, hazy, or foggy skies; excellent for contrast; minimizes eyestrain; dis­torts color (images look yellow-orange).

• Yellow—Improves contrast and depth perception in low light; good for overcast days.

• Red—Excellent depth perception in low light; contrast objects against blue or green back­grounds.

• Mirrored—Reflects high-intensity light to reduce glare; available in various colors.

When purchasing sunglasses, make sure you read the label.  You want to look for 99 or 100 percent UV pro­tection, and sunglasses that are close fitting to the face to pre­vent UV rays from filtering in.

Don’t be misguided by price: higher priced sunglasses usually reflect fashion, and not UV protection. Remember that dark-colored sunglasses don’t nec­essarily provide better protection because the chemical coating applied to the lens responsible for UV protection is clear.

Protect your eyes whenever you go outside, no matter how briefly.

You can be in the sun without sunscreen for up to 20 minutes a day.  This is extremely variable depending on your genetics. The darker and thicker your skin, the longer the sun exposure needed to start sun radiation damage. For freckling individuals, sun exposure may cause damage very quickly, even in less than 5 minutes. This is why it is very important to protect your skin with sunblock when you are outside.  But what if you don’t want to use sunscreen… What other protection can I use?

Wear Sunglasses

Sunglasses protect the sensitive skin around the eyes and also helps to prevent cataracts. The best sunglasses block 99 to 100% of UVA and UVB rays. Wrap-around sunglasses and styles that fit close to the eye are especially good because they prevent the sun’s rays from coming in through the sides.

Wear a Hat

A tightly woven hat with a 4-inch brim all the way around, helps shade your face, ears, and the back of your neck. Baseball caps leave your ears and neck exposed.

Wear Appropriate Clothing

This means long-sleeve shirts, and long pants. The colour of the fabric can also make a difference; as a general rule, lighter coloured fabrics let more UV rays through than darker coloured fabrics. Also the tighter the weave, and the thicker the fabric, and the better the clothing is at blocking  UV rays.

Fabric Matters in Regular Clothing

Nylon – highly effective protection, Watch out for “stretchy” fabric – clothing that the weave expands when the material stretches, will let in more UV rays, so the correct fit is very important in elastic clothing.

Wool – moderately effective

Silk – moderately effective

Cotton, rayon, and hemp – least effective (unless chemically treated)

Denim (heavy weight) – superior protection

Lightweight cotton jersey knit, typical of T-shirt fabrics: SPF 4 (white) / 18 (dyed blue).
Heavy cotton twill – 8 oz. denim: SPF 12 (white) / 100 (dyed blue). Blue jeans eliminate 100% UV rays

Buy dark coloured clothing with tight-knit weaves or clothing with UPF.

UPF Clothing

The UPF rating is to clothing what the SPF rating is to sunscreen. The UPF rating is applied to textiles that protect your skin from the sun.  SPF measures only how much UVB is blocked, but not UVA (unless it is labeled “broad spectrum”). UPF clothing blocks both types of damaging rays.

UPF clothing either blocks or absorbs UV radiation to protect your skin.  The UPF rating is based on a fabric’s content, weight, color, and construction.

UPF rating for clothing:

15 to 24 – Good
25 to 39 – Very Good
40 to 50 – Excellent
It’s best to choose clothing with a UPF rating of 30 or higher; UPF 50 blocks 98 percent of UV rays.

Whether you buy UPF clothing, or wear what you have in your closet, make sure that you are protected from the suns damaging rays.