Eyeglass lens terms can describe different things:
the lens design, the lens material, or an added lens
treatment or optical feature.
Tinted, mirrored, anti-reflective, polarized and
photochromic lenses are common lens options, but they
do not all describe the same type of lens technology.
For example, a prescription lens can use a single vision
or progressive design while also having an anti-reflective
coating, a tint, polarization or a photochromic feature,
depending on the lens and available options.
If you are ordering prescription lenses,
first follow your prescription requirements and then compare
the lens features available for your prescription, frame and
intended use.
Important:
Lens color, darkness and reflective appearance do not by
themselves tell you how much UV protection a lens provides.
When UV protection is important, check the actual UV rating
or product specification rather than judging the lens by
appearance alone.
Common Lens Options at a Glance
|
Lens Option
|
What It Does
|
Common Use
|
|
Tinted
|
Adds color and reduces selected amounts of
visible light depending on the tint.
|
Sunglasses, fashion or specific lighting
preferences.
|
|
Mirrored
|
Uses a reflective surface coating that
reflects part of the incoming light and
creates a mirrored appearance.
|
Commonly used on sunglasses for bright
outdoor conditions and style.
|
|
Anti-Reflective
|
Reduces reflections from the lens surfaces
and allows more visible light to pass through
the lens.
|
Prescription and non-prescription lenses
where reduced surface reflections are
preferred.
|
|
Polarized
|
Reduces strongly reflected glare from
surfaces such as water, snow and roads.
|
Outdoor activities and environments where
reflected glare is noticeable.
|
|
Photochromic
|
Changes tint as lighting conditions change.
The degree and speed of darkening vary by
lens technology.
|
People who want lenses that adapt between
different lighting environments.
|
Tinted Lenses
Tinted lenses contain color that changes how much visible
light passes through the lens. Tints can range from very
light to dark and may be available in different colors
depending on the lens.
They are widely used in sunglasses, but tint can also be
selected for appearance or particular lighting preferences.
A darker tint does not automatically mean that the lens
provides greater UV protection.
Remember:
If you need sun protection, check the stated UV
protection of the lens separately from its tint color
or darkness.
Mirrored Lenses
Mirrored lenses have a reflective coating on the outer
surface of the lens. The coating reflects part of the
incoming light and gives the lens its characteristic
mirror-like appearance.
Mirror coatings are commonly used on sunglasses and can
be combined with different lens colors. The appearance
and amount of light reflected depend on the particular
lens and coating.
A mirror finish should not be used by itself to judge
UV protection. Check the lens specification when UV
protection is part of your buying decision.
Anti-Reflective Coating
An anti-reflective coating,
often called an AR coating,
is applied to a lens to reduce reflections from
its surfaces.
By reducing unwanted surface reflections, an AR coating
can increase the amount of visible light transmitted
through the lens and make the lens surface appear less
reflective.
Modern anti-reflective coatings can use different
materials and multilayer designs. They should therefore
not be defined as one specific chemical coating.
Do not use reflection color as a test:
A green, purple or other residual reflection is not
a reliable consumer test for determining the complete
performance or specification of an AR coating.
Polarized Lenses
Polarized lenses are designed to reduce strongly reflected
glare, particularly light reflected from horizontal
surfaces such as water, snow and roads.
This makes polarization a useful feature for many outdoor
activities where reflected glare is noticeable.
Polarization and UV protection are different
lens properties.
Do not assume that a lens provides a particular level
of UV protection simply because it is polarized.
Check the product's UV specification separately.
Photochromic Lenses
Photochromic lenses are lenses that change tint as
lighting conditions change. They are generally clearer
in lower-light indoor conditions and become darker when
exposed to the outdoor conditions that activate the
particular photochromic technology.
The speed, degree of darkening and response to different
lighting environments can vary between photochromic lens
products and technologies.
Because photochromic technologies differ, check the
specific product description rather than assuming that
every photochromic lens uses the same chemical process
or performs identically.
Lens Design vs. Lens Material vs. Lens Treatment
These terms are often mixed together when people discuss
eyeglass lenses, but they describe different parts of
the lens.
Lens Design
Lens design describes how optical power is
arranged across the lens.
Examples include
single vision, bifocal and progressive
lenses
.
Lens Material
Lens material describes the physical material
from which the lens is made.
Different materials can have different
refractive indexes, thickness, weight and
other physical properties.
Lens Treatment or Feature
Treatments and optical features modify how
the finished lens handles light or how its
surface behaves.
Examples include
anti-reflective coatings, tints,
mirror coatings, polarization and
photochromic features
.
How to Choose Eyeglass Lens Options
When choosing lenses, start with the optical correction
required by your prescription and then consider additional
lens options according to how you plan to use your glasses.
-
Your prescription:
choose a lens design and power that match your
prescription requirements.
-
Everyday use:
consider whether the glasses will mainly be used
indoors, outdoors or in both environments.
-
Glare:
polarization may be useful when reflected outdoor
glare is a major concern.
-
Surface reflections:
an anti-reflective coating can reduce reflections
from the lens surfaces.
-
Changing light:
photochromic lenses may be considered when you prefer
lenses that adjust their tint as lighting conditions
change.
-
Sun and UV protection:
verify the stated UV rating or product specification
rather than relying only on lens darkness, color,
polarization or a mirror finish.
-
Availability:
not every feature is available with every prescription,
frame or lens material, so review the options shown
during lens selection.
Frequently Asked Questions About Eyeglass Lenses
-
What is the difference between a lens type and a lens coating?
-
A lens design describes how optical power is arranged in the lens, such as single vision or progressive. A coating is an additional surface treatment, such as an anti-reflective or mirror coating. A prescription lens can combine a lens design with one or more available coatings or features.
-
Are tinted lenses and polarized lenses the same?
-
No. Tint changes lens color and visible light transmission, while polarization is designed to reduce strongly reflected glare from surfaces such as water, snow and roads. A lens may combine tint and polarization, depending on the product.
-
Do darker lenses always provide more UV protection?
-
No. Lens darkness does not tell you how much UV protection a lens provides. Check the stated UV rating or product specification when choosing sunglasses or other lenses for UV protection.
-
What does an anti-reflective coating do?
-
An anti-reflective coating reduces reflections from the surfaces of an eyeglass lens and increases the amount of visible light transmitted through the lens.
-
What are photochromic lenses?
-
Photochromic lenses change tint as lighting conditions change. Their degree and speed of darkening can vary depending on the particular lens technology and environment.
-
Can prescription lenses also be polarized or photochromic?
-
Prescription lenses can be available with features such as polarization or photochromic technology, depending on the prescription, lens material, frame and specific lens options offered.
