is estimated, that in the U.S. 6% of the 33 million
contact lens wearers experience contact lens related
eye disorders. They are a major challenge since
these disorders can affect the eye and/or aggravate
pre-existing eye disorders.
Problems that arise from using contact lenses
can be caused by,
the lens care system used, contact lens material,
spoilage characteristics of the lenses, and patient
Another category of causes of contact lens
related eye disorders involves exacerbation of
pre-existing eye conditions. Conditions including
allergies, dry eyes, blepharitis
and eyelid abnormalities can be made worse by
contact lens wear. These disorders should be
distinguished from disorders directly caused
by contact lens wear.
Contact related disorders
Spoilage: Spoilage affects mostly soft and therapeutic
contacts. The causes are tear chemistry, inappropriate
lens cleaning methods, lens material and environmental
Spoilage causes poor visual quality, poor wetting
of lenses, poor fit due to changed eye parameters,
irritation, deposits, and reduced oxygen permeability
through the lenses to the eye. The more severe
disorders include eye inflammation and allergy.
Deposits: Deposits on contact lenses are formed
from tears. Rubbing of these deposits against
inflammation and allergies. Environmental contaminates
like oils, dust and smoke can also form deposits.
The deposits form a filmy coating. Proper cleaning
regimen is needed to remove deposits. Wearing
daily wear 2-week disposables may reduce deposits.
In severe cases, change over to RGP lenses is
Warpage: Warpage refers to basic changes in
the original fitting parameters. Warpage is commonly
caused by excessive squeezing by the fingers
while cleaning, and exposure to excessive heat.
Warped lens can cause warped cornea, inducing
irregular astigmatism. Warpage can also lead
to poor vision and spectacle blur. Corneal warpage
occurs more with PMMA lenses. It takes days to
months to resolve the corneal warpage.
Damage: Damages, like tears, cracks and chips
in the lenses are caused during manufacture or
handling by the wearer. Damages cause causing
eye irritation. Depending on the location of
the damage, the patient may or may not have symptoms.
The common symptoms are foreign body sensation,
tearing and blurred vision. On examination conjunctival
injection, superficial punctuate keratitis and
corneal defects are usually seen. Sometimes bacteria
enter the cracks on the lens, causing infection.
Treatment includes discarding the old lens and
improved lens handling. Lubrication is advised
if the corneal epithelium has been damaged.
Allergic conjunctivitis is the most common pre-existing
factor causing eye disorders. Both seasonal and
perennial allergens are the causes. Symptoms
include itching, tearing, burning, swollen lids
and pressure around the eyes. Wearing of contacts
may increase contact lens intolerance. Lens wear
therefore should be restricted. Treatment includes,
firstly, removal of the offending agent. Artificial
vasoconstrictors or antihistamines may be used
to reduce the symptoms. Combination antihistamines – mast
cell stabilizers are very effective and additionally
allow continuous use of the contacts. In severe
cases, lens wear should be discontinued totally,
until the symptoms subside.
Vernal keratoconjunctivitis is a recurrent condition
occurring in young people between 5 to 20 years
of age. It may be seasonal or perennial. Symptoms
include itching, irritation, redness, light sensitivity
and blurred vision. Some affected people have
limbal thickening and giant papillae.
cornea can show
epithelial damage or a shield ulcer among other
possible problems. Treatment includes use of
topical antihistamines, vasoconstrictors and
mast cell stabilizers. In
severe cases, topical steroids are used to get
a rapid response. Topical mast cell stabilizers
with steroids reduce the amount of steroids needed.
Since it is a recurrent childhood condition steroid
use must be restricted. The condition resolves
on reaching adulthood and the patient can resume
Atopic conjunctivitis is seen with atopic dermatitis.
It develops during childhood, in the teens or
in the early 20s and peaks between ages of 30
and 50. Symptoms include tearing, itching, light
sensitivity and sometimes lid swelling. Cornea
shows keratitis, vascularization and opacity.
Treatment includes quick tapering doses of oral
It is the most severe form of eye allergy
and its cure is uncertain. The patient, therefore,
should not be allowed to wear cosmetic contacts.
Blepharitis is a chronic, long lasting eyelid
inflammation involving eyelashes and oil glands.
It can also lead to contamination of the contact
lens surface by pathogens (bacteria). Symptoms
include itching, burning and
includes good eye hygiene, eyelid cleaning and
use of antibiotics. Blepharitis
affected patients may wear cosmetic contacts
but these should be discarded if the symptoms
Dry eyes are due to reduced tear production
which leads to many eye surface problems. Hormonal
oral medications and systemic diseases can affect
the severity of the condition. Symptoms include
burning, tearing (counter intuitive but true),
foreign body sensations, and blurred vision.
Dry eyes may
intolerance. Patients with severe dry eye should
not wear contacts.