Do clouds block UV rays?

According to the Doctors of Optometry Facebook page, UV rays are so strong, up to 90% of rays can penetrate through the clouds. They can also reflect off surfaces such as sand, snow and water. No matter the day, always protect your eyes from invisible UV rays.

A significant amount of UV rays can actually enter your eyes even you are wearing UV blocking eyeglasses.  That's because those glasses block the UV rays that come at them from the front but UV rays can reflect of the back of the lens (the side of the lens that is closest to your eye) and into your eyes.  To stop that, you should wear advanced UV protection lenses with an ESPF (eye-sun-protection factor) of 25 or higher.

Learn more here.

Skin cancer around the eyes

Optometrists are always mindful of the possible development of skin cancer in the skin surrounding the eyes.

In fact, the eyelid region is one of the most common sites for nonmelanoma skin cancers. Skin cancers of the eyelid, including basal cell carcinoma, squamous cell carcinoma, and melanoma, account for five to 10 percent of all skin cancers.  The best way to prevent this type is skin cancer is to reduce your exposure to UV radiation which comes with sunlight.

The best way to do that is to wear sunglasses and eye glasses with advanced and more effective UV technology built into the lenses.  With traditional lenses, UV radiation is blocked when it hits the front of the lens but you get 50% of your UV exposure from radiation that reflects into your eye from the back of the lens.  New lens technology can prevent the latter and give you vastly superior protection. Ask for lenses that have an ESPF rating.

To learn more about skin cancer around the eyes, read the following studies:

• Cook BE Jr, Bartley GB. Treatment options and future prospects for the management of eyelid malignancies: an evidence-based update.Ophthalmology 2001 Nov; 108(11):2088-98.

• Abraham J, Jabaley M, Hoopes JE. Basal cell carcinoma of the medial canthal region. Am J Surg1973; Oct; 126(4):492-5.

Related articles:

The myth of "100% UV Protection" eyeglass lenses

May 19, 2012

Parents take better care of their own eyes than the eyes of their children

Sep 26, 2012

May Is UV Awareness Month: Be Sun-wise With Your  Eyes

May 01, 2012

Parents take better care of themselves than their kids 

May 24, 2012

The most fashionable way to prevent disease and eye cancer

May 25, 2012

Sunglasses buying tips 

Jun 01, 2012

New surgery turns brown eyes blue permanently - what about the cancer risk?

Nov 14, 2011

April is women's eye health and safety month - See For Life

Apr 11, 2012

Kids' Sunglasses Warning - See For Life

Jun 01, 2011

map | diections | FREE parking | book an appointment 

What is the best sunglasses lens in the world? Check the ESPF: eye-sun protection factor

What is ESPF?

ESPF is eye-sun protection factor - a way to measure the degree of UV protection provided by an eyeglass lens that was developed by the French optical company Essilor.

The higher the number, the higher the UV protection of a lens.  Most lenses that tout themselves as 100% UV protection, only block UV rays that hit the lens from the front - they block 100% the UV rays that hit the lens from the front only.  Those are ESPF 5 or 10 lenses.  Advanced UV technology lenses go up to ESPF 25 for a clear lens and ESPF 50 for a tinted sun lens.

With traditional UV lenses (the ones that only block rays form the front of the lens) you still get lots of  UV exposure from rays that reflect off the back of the lens and into your eyes, as shown in this diagram:

Some lenses, like Crizal Forte UV shown in the diagram, block UV rays that reflect of the back of the lens.  This gives you more than twice the UV protection of tranditional lenses.  Crizal Forte UV is an ESPF 25 lens.  It is the highest level of UV protection that you can get in a clear lens.

What is the best sunglasses lens?

To get the maximum protection, ESPF 50, you need to go with the Crizal Sun UV lens, which is the only (as far as we know) dark tinted lens that blocks UV rays from the front as well as reflected UV rays.  See the chart tat the end of this post for a list of the available ESPF 25 and ESPF 50 lenes.

Why worry about UV exposure?

UV exposure to the eyes increases the risk of diseases like cataracts and macular degeneration, which can cause permanent vision loss.  It also leads to skin cancer around the eyes, which is the most common kind of skin cancer.

Other UV related dangers include Pingueculae (small yellowish bumps on the white of the eye) and pterygium (opaque growth over the surface of the cornea). The more UV exposure you have during your life, the more likely you are to develop one of these damaging conditions.

Here is what vision is like with macular degeneration:

Here is what vision is like with cataracts:

ESPF 25 and ESPF 50 Lenses

Related Articles

Why do parents take better care of their own eyes than those of their children?
Sep 26, 2012

Skin cancer around the eyes - See for Life
Oct 24, 2012

Sunglasses buying tips - See for Life
Jun 01, 2012

Skin cancer around the eyes 
Oct 24, 2012

Sunglasses buying tips - See for Life
Jun 01, 2012

Kids' Sunglasses Warning - See for Life
Jun 01, 2011

What is the best eyewear for kids? It's what eye doctors choose for their own kids.

Our sister blog, KidsVision.ca asks, "What is the best eyewear for kids?"  The eye wear that eye doctors choose for their own children  reflects a doctor's concern for health, safety and effective vision correction.  Find out what eye doctors choose for their own kids. Read more...

How eye glasses totally change your look, enhance your vision and prevent cancer

Eye-wear can totally change our entire look in addition to enhancing your vision, protecting your eyes from harmful UV radiation, preventing wrinkles and getting rid of visual fatigue and headaches and preventing skin cancer.  What a great invention!

Visit www.freeglasses.ca to find out you you can get free eyeglasses from our Vancouver Optometry clinic.

Parents take better care of themselves than their kids

Any parent would want to took after their child's health at least as well as they look after their own. But a parent can only do this if they have the right information.

Kids are not being protected from UV radiation

According to a new report issued by The Vision Council in May 2012, this is not happening when it comes to keeping eyes healthy by protecting them from harmful UV radiation. The report shows that while 73% of adults do wear sunglasses, only 58% of them make their children wear sunglasses.

UV exposure over time causes eye disease and vision loss

The report suggests that too many people still do not understand the serious damage that UV exposure can have on your eyes. Even fewer realize that it is cumulative exposure over time – which happens on both sunny and cloudy days – that leads to vision threatening diseases. One such disease, macular degeneration, leads to permanent vision loss and their is no cure.

The solution is to wear sunglasses and regular eye glasses with proper UV protection. Kids need this more than adults because the lens of a child’s eye is not as good as blocking UV rays as the lens of an adult eye.

What cataracts and macular degeneration look like

Wearing sunglasses is a serious preventative health measure. Here is what macular degeneration can do to your vision:

UV damage also causes cataracts. Here is what cataracts can do to your vision:

The right lens technology makes the difference

It is also important to realize that not all lenses are the same at blocking UV rays.  Even lenses that claim 100% UV protection actually don't deliver on that promise.  However, newer lens technologies are tackling that problem and provide much better UV protection.  To learn more read our previous post on new UV lens technologies.

The myth of "100% UV Protection" eyeglass lenses.

Image: NASA

In honor of May as UV Awareness Month, See for Life is going to bust one of the biggest UV myths out there.  But first, if you want to learn more about UV exposure and eye health, read our post on UV basics and the diseases that UV exposure causes, just click here.

Lenses for glasses and sunglasses often tout "100% UV protection".  Does that mean that no harmful UV rays at all enter you eye?  No.  It means that the lens blocks all the UV rays that hit the front of the lens.  However, recent studies have shown that UV rays still enter your eyes because up to 50% of your UV exposure comes from rays that reflect off the back of the lens (the side closest to your eye) and into your eyes!  On top of that, we get 40% of our UV exposure on cloudy days.  So even if the sun is not shining bright, there is still lots of ultraviolet radiation pouring into your eyes even if you have standard UV protection lenses.

This means that so-called "100% UV protection lenses" only really give you around 50% protection.  That's better than nothing.  But there are new lens technologies on the market that can take care of all that reflected UV light so that you really do have total UV protection (or close to it).

The only lens that we are aware of that gives you total UV protection is the Crizal Forte UV lens (and other Crizal lenses that have the advanced UV protection). Here is a diagram that explains how it works.

You may think that you are not getting enough safety bang for your buck when you buy sunglasses.  And you would be right.  But there are some things you can do to get more out of your sunglasses.  Many sunglasses (even by the big designers like Gucci and Versace)  can accept prescription lenses and your eye doctor will be able tell you which models these are and how you can order them with custom lenses - the kind of lenses that you can get with technology like Crizal Forte UV. 

Of course, if you wear glasses normally you can get prescription sunglasses with Crizal Forte UV.  However, if you have perfect vision you can order your sunglasses with "plano" lenses, which are lenses that have no vision correcting power.  You can even take your old sungalsses to the optometrist and get new Crizal Forte UV lenses put into them.

UV exposure is very dangerous and over time it can lead to vision loss from diseases like cataracts and age related macular degeneration.

Here is what vision is like with macular degeneration:

Here is what vision is like with cataracts:

To learn more about UV exposure, read our post on UV basics here.

Download our UV education brochure by clicking on the image below.

Related Articles

What is the best sunglasses lens in the world?
April 28, 2013

Why do parents take better care of their own eyes than those of their children?
Sep 26, 2012

Skin cancer around the eyes - See for Life
Oct 24, 2012

Sunglasses buying tips - See for Life
Jun 01, 2012

Skin cancer around the eyes
Oct 24, 2012

Sunglasses buying tips - See for Life
Jun 01, 2012

Kids' Sunglasses Warning - See for Life
Jun 01, 2011

May Is UV Awareness Month: Be Sun-wise With Your Eyes

The same sun rays that lead to skin cancer and premature aging of the skin are just as bad for your eyes. The culprit is Ultraviolet (UV) Rays and because May is National UV Awareness Month we want everyone to be “Sun-wise With Your Eyes”

Unprotected exposure to UV radiation can cause photokeratitis, which is basically a sunburn of the eyes marked by painful, red eyes and a sensitivity to light.The symptoms usually clear up quickly and cause no permanent damage to the eyes. 

However, growing evidence suggests that long-term exposure to UV rays can lead to macular degeneration and cataracts , serious eye conditions that can cause vision impairment or loss.

Other UV related dangers include Pingueculae (small yellowish bumps on the white of the eye) and pterygium (opaque growth over the surface of the cornea). The more UV exposure you have during your life, the more likely you are to develop one of these damaging conditions.

Doctors suggest the following to protect the eyes from serious damage:

•If at all possible, limit your time in the sun.

•Wear a wide-brimmed hat

•Wear sunglasses that filter 99% of UV rays

Don’t forget the children. Children are especially susceptible to eye damage from the sun. The lenses in their eyes do not block as much UV radiation as in adults.  Follow the same precautions as you would for an adult, but be sure to choose sunglasses that fit their smaller faces, have impact-resistant lenses, and have lenses large enough to shield the entire eye.