Guide to Eye Infections - Types, Causes, Worrying Symptoms
Eye infections are usually easy to spot
because of persistent itching, apparent redness, and other bothersome
symptoms. The tricky part is knowing to distinguish a simple case of
pink eye from a dangerous eye infection that has the potential to cause
permanent vision loss. The human eye is an extremely complex organ that
consists of 10 general components, any of these parts can become the
breeding ground for various germs - bacteria, viruses, and even fungi.
While minor eye infections can heal on
their own, others can inflict serious damage and need urgent medical
care. In this article, we review 6 common types of eye infections and
the signs of a dangerous eye infection.
6 Common Types of Eye Infections
Conjunctivitis 
Also known as pink eye, conjunctivitis is the infection of the
conjunctiva, a thin clear membrane that protects the eyelid. Pink eye is
by far the most widespread and well-recognized eye infection. Most
cases of pink eye are caused by viruses, but bacterial and allergic
conjunctivitis are also common.
In most cases, conjunctivitis is easy to spot because it makes the eye
turn pinkish and produces a viscous discharge that is the thickest when
you wake up. The good news is, most cases of pink eye will go away on
their own within days or a few weeks, although you may need to get
antibiotic eye drops to clear up bacterial conjunctivitis.
Blepharitis
Blepharitis is an inflammation of your eyelids. It occurs when the tiny
oil glands at the base of your lashes get clogged up. Patients with
blepharitis experience burning in the eyes and they may notice
dandruff-like flakes or crusts along the waterline and lashes.
Blepharitis can also make your eyes sensitive to light and cause blurry
vision.
People with oily skin, dandruff, and rosacea are more likely to get this
condition. Since most cases are bacterial, you’ll likely need special
eye drops to recover from blepharitis.
Styes and Chalazia
Both of these conditions affect the eyelids and look very similar,
although a chalazion is a blocked oil gland and a stye is an infection
of the eyelash follicle. The conditions appear as swelling or red bumps
on the eyelids that are itchy and painful to the touch.
Both styes and chalazia are usually not an emergency and can be treated
at home by applying a clean, warm, damp compress to the affected eye for
20 minutes several times a day. It should disappear in about a week.
However, some chalazia can grow so large that they limit your vision and
may require surgical removal.
Keratitis
Keratitis affects the cornea, a transparent domed membrane of the pupil
and iris. Any type of germ, be it a virus, bacterium, fungi, or parasite
can trigger keratitis, and the dangerous condition can cause lasting
vision damage if ignored. Note: severe dry eye can also lead to
keratitis.
Corneal infections are extremely painful and accompanied by redness,
swelling, blurry vision, and light sensitivity. Keratitis is a medical
emergency that requires urgent diagnosis and treatment. If you don’t
treat keratitis, it will get worse and may lead to blindness.
Uveitis 
Uveitis is an inflammation of the center of the eyeball - the uvea -
that supplies blood to the retina, the part of your eye that perceives
visual information. Eye injuries, viruses, and immune conditions like
rheumatoid arthritis make you more likely to develop uveitis.
The condition causes light sensitivity, blurry vision, “floaters” in the
visual field, and redness that can come and go. Uveitis doesn’t always
cause pain - so it’s more likely to be reported later. If you experience
any of these symptoms, seek medical help, as uveitis can damage vital
tissues and cause blindness.
Endophthalmitis
Our eyeballs are filled with two types of fluids that help maintain the
shape of the eye. When those fluids become infected, a condition called
endophthalmitis develops. This can happen as a result of eye injury or
as a complication of eye surgery. Endophthalmitis is characterized by
blurry vision, pain, redness in and around the eye, sensitivity to
lights, and partial or complete vision loss.
Since the condition can develop very fast, these symptoms shouldn’t be
ignored and always requires urgent medical care to prevent blindness or
vision loss.
What are the common symptoms of an eye infection?
We have already outlined some of the main symptoms of eye infections
above, but here is a concise list that may further help you. Note that
symptoms can occur in both eyes or one eye only. We marked the signs
that require emergency care as urgent.
What you may feel:
Pain
Itchiness
Burning
A feeling that there is something in your eye
Light sensitivity
Your eyelid is painful or tender when you touch it
Fever
Swollen lymph nodes on the neck.
What you may see:
Your eyes produce more tears
Yellow, clear, or green discharge
Crustiness around the eyelashes or corner of the eye
The "whites" of your eyes are pink or red
Swollen or red eyelids
Hypopyon - a yellow or greenish substance at the bottom of the iris
(the colored part of the eye), (urgent)
Cloudy cornea (urgent).
Changes in vision:
Blurry vision (urgent)
“Floaters” in the visual field
Vision loss (urgent).
What are the causes of eye infections?
Contact lens wearers, smokers, and people with weakened immune systems
have a higher risk of eye infections. The most common causes of eye
infections are as follows:
- Contaminated contact lenses - storing contacts improperly is one of
the most common causes of eye infections ranging from pink eye to
keratitis. The same can happen if you wear contacts too long or sleep in
your contacts.
- Eye injuries or complications of eye surgery, such as cataract
removal.
- Using expired or contaminated eye makeup.
- Washing your face with contaminated water.
- Not washing your hands after frequenting public spaces, especially
restrooms.
- Other people - you can get conjunctivitis by coming in contact with
other people
who have it.
In summary, there are so many common eye infections most of us have
never even heard of. While some of these infections - like styes or
conjunctivitis - are no cause for concern and will go away on their own,
others can develop very quickly and lead to permanent vision loss. If
you experience blurry vision, severe pain, persistent redness, or vision
loss, seek emergency care immediately.