Aqua Technologies Biomedical Research/Education Division
The Natural Solution to…
Contact Lens Discomfort
Contact lenses, those handy-dandy little vision aids,
make the difference for 28 million people between seeing clearly in all
directions, or being confined to inconvenient and distorting eyeglasses or worse.
With the many choices and technological advances available these days, contact
lenses should continue to benefit millions of people who have less-than-perfect
the catch: While a few contact lens users are able to wear their lenses for
days or weeks at a time with no problem, such individuals are the exception. Many
people can tolerate contact lenses only for short periods, and many cannot
tolerate them at all. Even for those who tolerate them
reasonably well, lenses frequently cause discomfort. This article will suggest a way to soothe much of the eye discomfort
caused by contact lenses:
The amazing tear film.
main thing to know about contact lenses is that they float on the surface of
the delicate and complex tear film that
covers the exposed parts of the eyeball, and they rely on the tear film’s
moisture (water content) to maintain their pliability, integrity and adherence.
The surface tension of the tear film’s moisture against the lenses prevents them
from falling out.
problem is that the most popular types of lenses deplete the tear film’s
moisture content and therefore interfere with healthy tear film functioning. Soft
lenses, and gas permeable lenses, have been compared to miniature sponges
because of the amount of tear film moisture they soak up. Even rigid lenses
deplete some tear film moisture. In addition, all lenses, even gas permeable,
reduce the amount of oxygen reaching the corneal surface. Rigid lenses restrict
oxygen the most, which is one reason they are smaller.
Tear film function and structure.
tear film that covers the exposed optical surface is amazingly complex,
considering that it is only about five microns (millionths of a meter) thick.
Tear film components:
Lipid layer. This topmost layer is
comprised of a very thin film of fatty oil that lubricates the eyelid and slows
moisture evaporation from the lower layers.
Aqueous layer. The middle and thickest
layer contains the vast majority of the tear film’s moisture. It also contains
electrolytes, proteins and bacteria-fighting antigens. It provides oxygenated
water to the cornea.
Mucin layer. This bottom layer is comprised of mucus that glues the
tear film to the optical surface.
Dry irritated eyes.
tear film moisture is depleted, the resulting abnormal changes can make the
eyes feel uncomfortable. The most physically irritating results of tear film
moisture loss are an over-concentration of electrolyte (salt) and proteins in
the aqueous layer. Insufficient
oxygen in the aqueous layer’s moisture
can also cause discomfort. Discomfort
can include itching, burning, irritation, eyestrain, headache, etc.
Soothing dry, irritated
dry, irritated eyes, whether caused by contact lenses, environmental
or bodily dehydration from illness or stress, is a simple and logical procedure:
Simply add moisture to the tear film!
In the past 110 years of medical eye care research, however, this has
proved more easily said than done.
problem has been getting the moisture past the overlying lipid layer. As it turns out, our eyes already know how to
accomplish this trick. The tear film is perfectly capable of extracting all the
moisture it needs from the humidity in the air, provided the air is reasonably
humid (70% at 70 degrees), and the humidity droplets are pure and unpolluted.
standard solution to the problem of dry, irritated eyes has been not humidity
but eyedrops. Since eyedrops
rely on chemical formulations and eyedroppers, they pose numerous drawbacks. The
typical eyedrop is ten times larger than the volume of
the tear film. When applied, the drop may flood and wash away the natural tear film,
including the evaporation-retarding lipid
layer. Despite their complex chemistry, formulated
eyedrops invariably lack one thing: The minute quantity of pure, natural,
pH-balanced water that is all the tear film really needs.
Additional drawbacks to eyedrops and wetting agents:
¨ You have to remove your
contact lenses to apply them.
¨ Some people are allergic to
the chemicals and preservatives.
¨ The eyedropper can cause
¨ Applying eyedrops is a slow, tedious procedure involving
you are doing, spreading the eyelids with your fingers,
head back, and aiming carefully. This can be unsafe if your
dirty or your hands unsteady.
In 2002, Bio-Logic Aqua Technologies Biomedical
Research introduced Nature’s Tears EyeMist, the first effective, all-natural
alternative to formulated eyedrops for dry, irritated
eyes. For the first time, millions of contact lens wearers are obtaining
instant relief from dry, irritated eyes…without eyedrops.
Tears EyeMist solved the problem of getting moisture in extremely minute
quantities past the lipid layer into
the aqueous layer. This is accomplished
very simply, by delivering the moisture as an ultra-pure, ultra-fine mist that
emulates the air’s natural humidity. The mist is sprayed towards the face rather
than into the eyes, enabling the tear film to extract exactly as much moisture
as it needs, no more and no less. In most
cases, all that is required to restore the tear film’s moisture content to full
volume and comfort, is two to five nanoliters
(billionths of a liter). That is far too little to apply with an
As an added benefit, delivering moisture in
the form of a mist oxygenates the moisture, thus increasing the aqueous layer’s oxygen content.
most beneficial component of eyedrops is the paraffin
or oil that can serve as a sealer to slow tear film moisture loss. Eyedrops are most effective as a moisture sealer when the
tear film’s moisture content is at full capacity. For best results, apply Nature’s
Tears EyeMist immediately before applying eyedrops,
and use the smallest amount of eyedrops possible. Since Nature’s Tears EyeMist has no dosage
limit, it may also be applied between eyedrop applications,
or when eyedrops are not convenient.