The eye is a complex organ
that converts light rays to images by means
of nerve impulses that feed into the brain.
To understand the eye and the eye disorders,
we can have the eye in two parts – the
anterior and the posterior.
The Anterior of the
eye consisting of the Sclera (the
white of the eye) and the Cornea.
The Posterior of
the eye consisting of the Retina
(the back of the eye), the Optic Nerve
(sending impulses to the brain translating
the image), the Iris (the fluid containing
colored part of the eye) and the Macula
(the highly sensitive area of the retina
responsible for focusing).
How Eye Works?
When you look at an object, light rays
are reflected from the object to the cornea.
Light rays pass through the cornea,
which does most of the focusing
The pupil in the Iris opens to let
in more light when its dark, and closes
to let in less when its bright
The lens fine tunes the focusing
Here at the retina, the light rays
are converted to electrical impulses that
are then transmitted through the optic
nerve, to the brain, where the image is
translated and perceived in an upright
position.
Cataract
Symptoms
Cloudy or blurry vision.
Colors seem faded.
Headlights, lamps, or sunlight may appear
too bright with glare. A halo may appear
around lights.
Poor night vision.
Double vision or multiple images in
one eye.
Frequent prescription changes in your
eyeglasses or contact lenses.
Causes
The above-mentioned symptoms can be those
of cataract. A cataract is a clouding of
the lens in the eye that affects vision.
Most cataracts are related to aging. Cataracts
are very common in older people.
Treatment
The symptoms of early cataract
may be improved with new eyeglasses, brighter
lighting, anti-glare sunglasses, or magnifying
lenses. If these measures do not help, surgery
is the only effective treatment involving
replacement of the cloudy lens with an artificial
lens. Cataract removal
is one of the most common and one of the
safest and most effective types of surgery.
Myth busters - Facts about
Cataracts
Cataracts do not travel from one eye
to the other
Cataracts are not caused by using the
eyes too much
Cataracts are not related to cancer
Cataracts cannot be treated or removed
with a laser
Glaucoma
Symptoms
At first, open-angle glaucoma has no
symptoms. It causes no pain. Vision stays
normal.
Slowly, symptoms like trouble focusing,
poor night vision, sensation of a blind
area, headaches associated with exercise,
halos around light and pain in eye - particularly
when associated with smoky vision.
Gradually, people start missing objects
losing their peripheral (side) vision
and seem to be looking through a tunnel.
Over time, straight-ahead vision may
decrease until no vision remains.
Causes
Increased eye pressure resulting from the
building up of fluid within the eye known
as intra-ocular pressure leads to the risk
for glaucoma in which the optic nerve gets
damaged. Glaucoma can be acute that occur
suddenly or chronic that continue to be
present for a long time.
Treatment
Glaucoma treatments include eye drops or
oral medication given in different combinations.
If medication is effective in controlling
the intra-ocular pressure, surgery is done
to create a new drainage channel for the
aqueous fluid to leave the eye.
Diabetic
Retinopathy
Symptoms
Diabetic retinopathy often has no early warning
signs. However, one should not wait for the
symptoms to occur. Be sure
to have a comprehensive dilated eye exam at
least once a year.
However in the most advanced stage of the
disease that is the proliferative retinopathy,
abnormal blood vessels can develop and leak
blood into the center of the eye, blurring
vision. You will see a few specks of blood,
or spots, "floating" in your vision.
Causes
High blood sugar levels can damage blood vessels
in the retina (the light sensitive nerve layer
at the back of an eye that helps to send images
to the brain). This damage to blood vessels
is referred to as Diabetic Retinopathy.
Treatment
With improved methods of diagnosis and treatments
like Laser Surgery or Virectomy people with
proliferative retinopathy have less than a
five percent chance of becoming blind within
five years. To prevent progression of diabetic
retinopathy, people with diabetes should control
their levels of blood sugar, blood pressure,
and blood cholesterol. You may need treatment
more than once to protect your sight.
The best protection
against Diabetic Retinopathy is early detection
of the disease to prevent vision loss, by
regularly visiting your ophthalmologist.
Refractive
Errors
Symptoms
Blurred Vision
Strain in the eyes
Headaches
Squinting
Causes
The above symptoms occur in case of refractive
errors where the length of an adult eye
ball which is normally 24mm, either increases
(Myopia) or decreases (Hypermetropia), causing
difficulty in focusing resulting in blurred
vision.
Myopia or nearsightedness usually develops
in the school going age and usually stabilizes
soon after. However Hypermetropia or farsightedness
can develop at any age.
Treatment
A thorough eye check up and accurately prescribed
eyeglasses or contact lenses can easily
counter these refractive errors.
Retinopathy
of Prematurity (ROP)
Symptoms
Premature infants do not have symptoms. External
signs develop only after disease has become
severe or progressed to retinal detachments.
Timely detection of ROP depends upon examination
by an ophthalmologist experienced in the examination
of premature infants.
Causes
Retinopathy of prematurity (ROP)
occurs in premature babies when abnormal blood
vessels and scar tissue grow over the retina
causing retinal detachment that is the main
cause of visual impairment and blindness.
ROP primarily affects premature infants that
are born before 31 weeks of gestation (A full-term
pregnancy has a gestation of 38–42 weeks).
The smaller a baby is at birth, the more likely
that baby is to develop ROP.
Treatment
Most babies' eyes with ROP do well
without any treatment. The most effective
proven treatments for ROP are laser therapy
or cryotherapy. In the later stages of ROP,
other treatment options include Sclera buckle
and Vitrectomy.
Periodic eye examinations will be necessary
as your baby grows, to ensure that the child's
vision is developing as normally as possible.
Age-related
Macular Degeneration
Symptoms
Blurry vision
Distorted vision
Straight lines appear wavy
Objects may appear as the wrong shape
or size
The loss of clear, correct colors
Difficulty reading
A dark, empty area in the center of
vision
If you are above 40 and you experience one
or more of these symptoms, it could be an
alarming signal for age related macular degeneration
(AMD).
Causes
Many older people develop macular degeneration
as a part of the natural aging process. Besides
age, there are several characteristics that
many people with macular degeneration seem
to have in common. These include family history,
smoking, or having blue or light colored eyes.
However, these may be the common factors in
people with macular degeneration, it is not
specifically known to what degree these characteristics
actually increase one’s risk for developing
macular degeneration.
Treatment
For individuals with macular degeneration,
it is highly recommended that a regular schedule
of eye examinations be maintained.
Warning Signs and
Risks for Vision Problems in Children
Squinting, closing or covering one
eye
Constantly holding materials close
to the face
Tilting the head to one side
Rubbing eyes repeatedly
One or both eyes turn in or out
Redness or tearing in eyes
Premature birth
Developmental delays
Family history of "lazy eye"
or "thick glasses"
A disease that affects the whole body
(such as diabetes, sickle cell or HIV)
If you notice any of these symptoms, make
sure your child sees an eye doctor for a
comprehensive children’s eye exam.
Keep in mind that not all children’s
vision problems can be diagnosed by you
or a school nurse; only an eye doctor has
the training and equipment to catch everything.
Low
Vision
Symptoms
Warning signs include:
Hazy or blurred vision
Loss of peripheral vision
Color confusion
Trouble reading, cooking or doing close-up
tasks
Difficulty recognizing familiar faces
Light sensitivity (complaints that lights
are too dim indoors)
Problems reading street signs or crossing
the street
Causes
Low vision results from the late diagnosis
of an eye disease resulting in visual impairment
that consists of partial sight or sight that
isn't fully correctable with surgery, pharmaceuticals,
contact lenses or glasses.
Treatment
Although there is no cure for low vision,
receiving the correct treatment is the first
step for vision improvement. As symptoms begin
to appear, contact an eye care professional
for a complete eye exam. After the diagnosis,
the eye care professional may prescribe treatments
and services and devices, such as magnifiers,
telescopes or speech synthesizers, to help
restore independence.
Eye
Protection & First Aid
SCEH team recommends
you to always use protective eye wear such
as glasses made for the purpose or heavy
goggles when doing anything that could endanger
SCEH team recommends you to always use protective
eye wear such as glasses made for the purpose
or heavy goggles when doing anything that
could endanger your eyes like active sports,
using power tools, working with chemicals
or house hold cleaners or with sprays or
radiant lights.
However in case of an eye injury, follow
the instructions below and immediately rush
to the nearest eye specialist.
Injury caused by small objects
If you get something in your eye, don’t
rub your eye.
Try blinking the eye under running water.
Objects in the lower lid can be removed
by pulling down on the skin just below
the eyelid.
Lift your upper eyelid outward and gently
pull it down over the lower lash causing
tears to flow washing the object out of
your eye repetitively.
If you are wearing contact lenses, remove
the lens and clean it thoroughly before
putting it back in your eye
If you are hit in the eye by a large
object such as a ball or a rock with high
speed can result in serious injury. Don’t
attempt to manipulate the eyes yourself.
See your ophthalmologist who can check
your eye for any internal damage.
Injury caused by chemicals and
dangerous liquids or powders
For chemicals or oils or other caustic
materials splashed in your eyes, immediately
flush your eyes with cool water for at
least 15 minutes.
If you are wearing contact lenses, remove
them immediately.
See your ophthalmologist immediately
and take along with you the chemical bottle
or the label to show to the doctor.
Injury caused by sharp objects
Never attempt to treat a cut, laceration
or penetrating eye injury (caused by knives,
hooks or pointed instruments) except to
stop the bleeding of eyelids or skin areas
around the eyes.
Seek immediate medical attention.
The best way to treat eye
injuries is to prevent them from happening
in the first place. Don't forget to be aware
of potential eye hazards and wear appropriate
eye protection.
Warning
Signs & Symptoms
SCEH team recommends
you to seek immediate medical attention
if you notice any of the following symptoms:
Sudden loss of vision
Blurred vision, even if gradual of time
Double vision
Flashes
Floaters in vision, which may look like
spots, flies, etc
Sudden marked distortion in vision
Severe redness of the eye
Severe pain in the eye, itching or dryness
Scratchy feeling or feeling that there
is something in the eye
Light sensitivity, especially if severe
or painful
Haloes around lights
Discharge, especially if heavy and with
pain or redness of the eye
Inability to see at night
Fluctuating vision
Protrusion of the eye, especially with
pain or loss of vision
