Eye Conditions Correctable by Refractive Surgical Procedures.
How Do You See?
Nearsightedness
(Myopia) - I can see things better up close than far away.
Farsightedness
(Hyperopia) - I can see things better in the distance than
up close.
Astigmatism
- I have blurred, sort of double vision in the distance and up close.
Presbyopia
- I have trouble reading but otherwise see pretty well far away.
Cataracts
- I have blurry vision far and near even with recently prescribed
glasses on. (This may mean you have cataracts)
I
can see things better up close than far away.
Nearsightedness
(Myopia). If you can see things clearly up close but not in the
distance, you are probably nearsighted. The medical term for this is
Myopia (and your eyes would be classified as Myopic). Nearsighted eyes
have a focus point up close and the vision is blurred in the distance
because light entering the eye focuses in front of the retina. Distant
objects are seen more clearly only with the help of glasses, contact
lenses or refractive surgery such as LASIK.
Surgical
Procedures to reduce the symptoms of Nearsighedness (Myopia).
Mild to Moderate Case of Nearsighted Eyes. Mild to moderate amounts
of nearsightedness (Myopia) where your prescription ranges from –
1.00 Diopters (thin glasses) on the low end and –10.00 Diopters
(thick glasses) or more on the high end can usually be corrected with
laser eye surgery (LASIK, PRK, LASEK, EpiLasik). A Diopter is the unit
of measurement of your prescription (The term Diopter is commonly referred
to with a “d”, so as an example, a prescription would read
“-1.00 D” or “-1.00 d”). This is accomplished
by reshaping the outer lens of your eye, your cornea, to refocus the
light rays on your retina.
Severe
Case of Nearsighted Eyes. If your prescription is between –8.00
Diopters and –20.00 Diopters your eyes may be best corrected with
the insertion of implants inside the eye. (The term Diopter is commonly
referred to with a “d”, so as an example, a prescription
would read “-8.00 D” or “-8.00 d”). These implants
are called Phakic Implants. The two Phakic Implants approved by the
FDA in the United States are the STAAR Visian implant and the AMO Verisyse
implant. Phakic Implants are placed inside the eye behind your cornea
and in front of your natural lens (the internal lens of your eye that
helps focus your vision from far to near). Phakic Implants can be combined
with another laser vision correction procedure to correct any residual
nearsightedness (Myopia) myopia or astigmatism not corrected by the
implant
I
can see things better in the distance but not up close.
Farsightedness
(Hyperopia). If you can see things better in the distance than up
close, you are farsighted. Farsighted or hyperopic eyes have a better
focus for distance but are often blurred even for distance, particularly
as you get older. Mild amounts of hyperopia (up to +2.00 Diopters to
+3.00 Diopters) in younger patients under 40 are often not noticed as
the eye has a mechanism (known as accommodation) for focusing the image.
(The term Diopter is commonly referred to with a “d”, so
as an example, a prescription would read “+2.25D” or “+2.25
d”). In general, after the age of 40, the amount of accommodation
decreases each year. Most mildly farsighted people around the age of
40 will first need glasses to read, but will eventually need glasses
for both near and distance (either with bifocals glasses or two separate
pairs, one for reading and one for distance). Higher amounts of hyperopia,
usually above +2.00 Diopters or +3.00 Diopters usually will require
correction with glasses or contact lenses early in life. These patients
will also require either two separate glasses or bifocals at around
age 40. Many people confuse Farsightedness with Presbyopia.
Surgical
Procedures for Farsightedness.
Mild
and Moderate Cases of Farsightedness (+2 Diopters to +5 Diopters). Laser
Vision surgery (LASIK, PRK, LASEK, EpiLasik) is capable of correcting
only up to about + 5 Diopters of farsightedness (Hyperopia).
Severe
Case of Farsightedness. Higher amounts of hyperopia (over +5 Diopters)
are usually best corrected by replacing the natural lens of the eye
with an implant. This procedure is similar to cataract surgery but when
it is performed only to correct the refractive error in eyes without
cataracts and this refractive surgery is referred to as Refractive Lensectomy
(RLE) or Clear Lensectomy (CLE).
I have blurred, sort of double vision in the distance and up close.
Astigmatism
– If you have astigmatism objects will be blurry and sort of double
both far and or near depending on whether you have nearsighted or farsighted
astigmatism.
Astigmatism
is a condition which occurs when the cornea has more than one curvature
(like a football as opposed to a basketball). These multiple curvatures
bend light differently and blurred vision is the result. Normal and
purely nearsighted (Myopic) or purely farsighted (Hyperopic) eyes have
one focal point. There is no such thing a pure astigmatism (where there
is no nearsightedness or farsightedness). With astigmatism, your eyes
have two different focal points. For nearsighted eyes with astigmatism,
both focal points are either in front of the retina or one is focused
on the retina and one in front of the retina. For farsighted eyes with
astigmatism, both focal points are focused behind the retina or one
is on the retina and one behind the retina. Although the word astigmatism
to a layman sounds somewhat more serious (stigmata) than nearsightedness
(Myopia) or farsightedness (Hyperopia), in reality most eyes have some
degree of astigmatism. Laser vision surgery is quite accurate at correcting
astigmatism of up to 4 or 5 Diopters in combination with the correction
of myopia or hyperopia.
Surgical
Procedures for Astigmatism
I have trouble reading but otherwise see pretty well far away.
Presbyopia refers to the natural
decrease in the eyes’ ability to see up close as we get older.
Even a patient with perfect vision (Emmetropia) all their life will
require glasses to help them read, usually at some point in the early
to mid forties.
Presbyopia starts to become noticeable usually at around age 40 and
it effects everyone. Nearsighted people (with Myopia) can usually remove
their glasses, hold the print up close, and read without glasses or
have bifocals put in their distance glasses. Slightly farsighted people
(with Hyperopia) will initially just need glasses to read but as they
get older, they will need them for near and far. Moderately or severely
farsighted people will already be wearing glasses for distance but will
now need either bifocals or two separate pairs of glasses. Normal sighted
people (called Emmetropia) who have never needed glasses will now need
them in order to read small print. Presbyopia gets worse as we get older
and thus patients require changes in reading power every few years.
If you are near age 40 or older, your laser eye surgeon should discuss
Presbyopia with you and explain your options to minimize this annoying
decrease in your near vision.
Surgical
Procedures to reduce the symptoms of Presbyopia.
*Conductive
Keratoplasty or CK and monovision LASIK are the only two procedures
approved by the FDA for treating Presbyopia, although this does not
mean PRK cannot be utilized. Although not FDA approved, PRK is considered
an “off label” use of the FDA-approved lasers. In fact,
many refractive surgeons used PRK and LASIK (which has now approved
by the FDA) in both nearsighted and farsighted eyes to create monovision,
with one eye focused for distance and the other focused for near vision.
Although
neither Conductive Keratoplasty (CK) nor laser vision monovision (LASIK
or PRK) “cure” Presbyopia, both procedures can reduce the
need for reading glasses for every day activities like reading a menu
or looking at a cell phone. With “Monovision” (or “blended
vision”) one eye is focused better for reading while the other
eye is focused primarily for distance. This is a common option for patients
over the age of 40 who are considering laser vision surgery to correct
their nearsightedness or farsightedness, with or without astigmatism.
Monovision is also an option for patients who have always had natural
excellent distance vision (Emmetropia) and desire to be able to read
without glasses. The only FDA approved procedure for the correction
of presbyopia in emmetropic eyes (normal eyes requiring no glasses)
is Conductive Keratoplasty (CK) where radio-frequency energy is applied
to 8 spots in the cornea to refocus one eye for a reading focus. The
CK procedure results in a milder form of monovision than the typical
laser procedure and it is often better tolerated by the patient because
the CK eye is not usually as blurred for distance as it would be with
laser induced monovision. However, not all patients are comfortable
with mono or blended vision and it is best to have this demonstrated
with either contact lenses or glasses before choosing this option
I have blurry vision far and near even with recently prescribed glasses
on. (This may mean you have Cataracts.)
Cataracts
are one condition that may explain why you have blurry vision far and
near even with recently prescribed glasses on. With cataracts, there
is a clouding of the normal internal lens of the eye and are more common
after the age of 60. Although many eyes have early cataract formation,
not all cataracts require surgery as patients with early cataracts can
have normal vision with no symptoms. These cataracts can be observed
until the patient begins to experience problems with their vision (with
glasses on) such as blurred vision for far and or near, and or glare
and difficulty driving at night. Other explanations for why you may
have blurry vision far and near even with recently prescribed glasses
include glaucoma or problems in the retina. Typically the doctors listed
at Trusted LASIK Surgeons can provide treatments for any of these conditions
and if they cannot, they can find you an expert capable of helping you.
Surgical
Procedures for Cataracts.