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Contact Lenses That Help Protect
Your Eyes
From Ultraviolet (UV) Light
When I talk with patients about their
contact lens options most have no idea that there are contact lenses that
actually block UV light. I equate it to "wearing sunscreen" for
their eyes. Living and playing in southwest, where we have 300+ days
a year with full sun and are at 6500 feet of elevation, protecting
ourselves from harmful ultraviolet light is a big concern for all of us.
Vistakon (with the AcuVue family of lenses) was the first manufacturers to
provide UV blocking in 1997. There lenses offer more protection than any
other contact lens and are the only lenses with the best FDA UV
rating of Class I. All AcuVue brand contact lenses (and a few
others) are FDA approved to help provide protection against transmission
of harmful UV radiation to the cornea and into the eye. But by far,
most lenses offer very limited protection; they on the average only block
approximately 10% of UV-A radiation and 30% of UV-B radiation.
Consumer research has shown that UV protection is an important lens
attribute for patients. In fact, 3 of 4 patients report that they
want UV protection from their contact lenses, and 1 of 2 say they would
switch brands for UV protection. But with the vast majority of
contact lens patients unaware that UV protection is available it's my job,
as your doctor, to inform my patients. Almost all of my patients are
wearing lenses that protect their eyes from harmful ultraviolet radiation.
I was talking with a contact lens company representative some time ago
when he asked me why I fit a different lens rather than his. I told
him that the major reason was the lack of UV blocking characteristics of
his lens. He sounded amazed at this response and said no one else
has ever used this as a reason- I can't really believe that. True,
there are just a handful of lenses available that offer protection, but
they are great lenses (high quality and very comfortable) that patients
absolutely love. Soft Lenses that
block UV Light:
● AcuVue family of lenses (highest FDA Class I rating
and block 96% UV-A, 99% UV-B)
●
AcuVue2
●
AcuVue Oasys
●
AcuVue Bifocal (the only
bifocal lens that blocks UV)
●
AcuVue2 Colours (the only
colored and tinted lens that blocks UV)
● Biomedics family of lenses (FDA Class II
rating and block 83% UV-A, 99% UV-B)
●
Biomedics 55 Premier Aspheric
●
Biomedics Toric (the only toric lens that
blocks UV)
● Bausch & Lomb's Precision UV (FDA Class II
rating and block 76% UV-A, 95% UV-B)
Rigid Gas Permeable (RGP) materials that block UV Light*:
● Boston family of materials
● Fluoroperm family of materials
● Fluorex family of materials
● Lagado family of materials (Denver)
*The list of RGP materials was compiled with the help of Dennis at
Duffens Optical in Denver. Thanks again Dennis for your consultation
expertise! Keep in mind that these RGP materials do have UV blocking
characteristics but are less effective than soft lenses because they are
much smaller in diameter and don't cover the entire cornea.
You will notice that most of these lenses are in the list of lenses that I
recommend and highlight on my website. I feel that UV protection is
a very important characteristic for my patients. However, because
contact lenses do not completely cover the eye and surrounding area, you
should continue to use UV-absorbing eyewear and a wide-brimmed hat as
while you wear one of these lenses.
Long-term exposure to UV radiation is one of the risk factors associated
with cataracts and
macular degeneration.
The amount of exposure is based on a number of factors such as
environmental conditions (altitude, geography, cloud cover) and personal
factors (extent and nature of outdoor activities).
There are other chronic UV induced pathology of the eye, for example,
carcinoma, pinguecula and keratitis. Pterygium is one particular
condition highlighted recently, and is thought to be caused by UV
radiation entering the eye obliquely and then refracted by the cornea.
UV protection is recommended for all patients and especially those who
participate in leisure or work activities that expose them to high levels
of UV radiation.
The Bottom Line: During your next contact lens fitting,
ask your doctor about lenses that offer UV protection. And if your
current lenses don't, then ask to be refit with ones that do. Also,
continue to wear UV blocking sunglasses, even on cloudy days, and a
wide-rimmed hat. Enjoy our great outdoors, but be smart to ensure
healthy eyes for years to come. ~RQ
The Following Information was Compiled from
the Web There are two
different Classes of UV Blocking
The ANSI and ISO standards classify UV-blocking contact lenses into two
groups based on the lens's absorptive capacity at its minimum thickness.
Class 2 UV-blockers must absorb at least 70 percent of UV-A and more than
95 percent of UV-B radiation. Class 1 UV-blockers must absorb a minimum of
90 percent UV-A and at least 99 percent UV-B radiation. Only products that
meet these standards may claim to be UV blocking.
"Not all contact lens lines offer UV protection, and, of those that do,
not all provide similar absorption levels," explains Pat Cummings, OD, VP,
Professional Affairs, VISTAKON. "All ACUVUE(R) Brand Contact Lenses offer
effective UV-blocking, and among contact lens brands, ACUVUE ADVANCE,
ACUVUE ADVANCE for ASTIGMATISM, and ACUVUE OASYS with more than 90 percent
of UV-A rays and 99 percent of UV-B rays blocked*+ are the only lenses to
achieve Class I UV blocking status."
Experts say it is difficult to isolate the exact amount of damage that UV
imposes on the eye over a long period of time. However, a number of
studies have shown that the effects of UV radiation are cumulative and may
increase the chance of developing eye problems later in life, including
cataracts and age-related macular degeneration, two leading causes of
reduced vision in the United States.
Because they cover the entire cornea and limbus, UV-blocking contact
lenses offer an added level of protection when worn with UV blocking
sunglasses. While many sunglasses will block UV rays that enter through
the lenses, most do not prevent unfiltered rays from reaching the eyes
through the sides, as well as the top, and/or bottom of the glasses. Due
to their inability to block these peripheral rays, some sunglasses block
as little as 50 percent of all UV radiation from reaching the eyes.
"It is just as important to block these peripheral UV rays," warns Dr.
Cummings. "UV-blocking contact lenses provide added protection by
effectively blocking sunlight that may enter the cornea from the top,
bottom, or sides of the glasses."
UV-Blocking contact lenses help provide protection against harmful UV
radiation. However, clinical studies have not been done to demonstrate
that wearing UV-Blocking contact lenses reduces the risk of developing
cataracts or other eye disorders.
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