keratitides

Your cornea is the outermost layer of your eye. It is clear and shaped like a dome. The cornea helps to shield the rest of the eye from germs, dust, and other harmful matter. It also helps your eye to focus. If you wear contact lenses, they float on top of your corneas.

Problems with the cornea include:

• Refractive errors
• Allergies
• Infections
• Injuries
• Dystrophies - conditions in which parts of the cornea lose clarity due to a buildup of cloudy material

Treatments of corneal disorders include medicines, corneal transplantation, and corneal laser surgery.

NIH: National Eye Institute

Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are:

• Conjunctivitis - also known as pink eye. Conjunctivitis is often due to an infection. Children frequently get it, and it is very contagious.
• Stye - a bump on the eyelid that happens when bacteria from your skin get into the hair follicle of an eyelash.

Symptoms of eye infections may include redness, itching, swelling, discharge, pain, or problems with vision. Treatment depends on the cause of the infection and may include compresses, eye drops, creams, or antibiotics.

If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful.

Some fungi reproduce through tiny spores in the air. You can inhale the spores or they can land on you. As a result, fungal infections often start in the lungs or on the skin. You are more likely to get a fungal infection if you have a weakened immune system or take antibiotics.

Fungi can be difficult to kill. For skin and nail infections, you can apply medicine directly to the infected area. Oral antifungal medicines are also available for serious infections.

It's frustrating to be unable to hear well enough to enjoy talking with friends or family. Hearing disorders make it hard, but not impossible, to hear. They can often be helped. Deafness can keep you from hearing sound at all.

What causes hearing loss? Some possibilities are:

• Heredity
• Diseases such as ear infections and meningitis
• Trauma
• Certain medicines
• Long-term exposure to loud noise
• Aging

There are two main types of hearing loss. One happens when your inner ear or auditory nerve is damaged. This type is usually permanent. The other kind happens when sound waves cannot reach your inner ear. Earwax buildup, fluid, or a punctured eardrum can cause it. Treatment or surgery can often reverse this kind of hearing loss.

Untreated, hearing problems can get worse. If you have trouble hearing, you can get help. Possible treatments include hearing aids, cochlear implants, special training, certain medicines, and surgery.

NIH: National Institute on Deafness and Other Communication Disorders

Herpes is an infection that is caused by a herpes simplex virus (HSV). Oral herpes causes cold sores around the mouth or face. Genital herpes affects the genitals, buttocks or anal area. Genital herpes is a sexually transmitted disease (STD). It affects the genitals, buttocks or anal area. Other herpes infections can affect the eyes, skin, or other parts of the body. The virus can be dangerous in newborn babies or in people with weak immune systems.

There are two types of HSV:

• HSV type 1 most commonly causes cold sores. It can also cause genital herpes.
• HSV type 2 is the usual cause of genital herpes, but it also can infect the mouth.

HSV spreads through direct contact. Some people have no symptoms. Others get sores near the area where the virus has entered the body. They turn into blisters, become itchy and painful, and then heal.

Most people have outbreaks several times a year. Over time, you get them less often. Medicines to help your body fight the virus can help lessen symptoms and decrease outbreaks.

Parasites are living things that use other living things - like your body - for food and a place to live. You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not.

Parasites range in size from tiny, one-celled organisms called protozoa to worms that can be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies can lead to Giardia infections. Cats can transmit toxoplasmosis, which is dangerous for pregnant women. Others, like malaria, are common in other parts of the world.

If you are traveling, it's important to drink only water you know is safe. Prevention is especially important. There are no vaccines for parasitic diseases. Some medicines are available to treat parasitic infections.

Your skin is your body's largest organ. It covers the entire outside of your body. There are many ways that your skin protects your body and helps keep you healthy. For example, it:

• Holds body fluids in, which helps prevent you from getting dehydrated
• Keeps out harmful germs, which helps prevent infections
• Helps you feel things like heat, cold, and pain
• Helps control your body temperature
• Makes vitamin D when the sun shines on it
• Shields your body against heat and light

There are many different problems and conditions which can affect your skin. Some of them can cause uncomfortable symptoms, such as itching, burning, redness, and rashes. They might also affect your appearance. Some of the more common skin conditions include:

• Acne, which causes pimples when hair follicles under your skin get clogged up
• Burns
• Cuts and scrapes
• Dandruff, flaking of the skin on your scalp (the top of your head)
• Eczema (atopic dermatitis), which causes inflammation, redness, and irritation of the skin
• Hives, which are red and sometimes itchy bumps on your skin
• Insect bites
• Psoriasis, which causes itchy, scaly red patches
• Skin cancer
• Skin infections

Since your skin protects your body in many ways, it's important to try to keep your skin healthy. For example, you can:

• Wear the right protective equipment, like gloves, long sleeves, knee and elbow pads, or helmets to protect against cuts, bumps and scrapes.
• If you do get a cut or scrape, clean it right away with soap and warm water. Put on a bandage to protect it while it heals.
• When you are spending time outdoors, wear long sleeves and pants and use insect repellant to prevent insect bites.
• Prevent sunburn by covering up and using sunscreen when outdoors.
• Wash your hands often with soap and water.
• When you take a shower or bath, use warm (not hot) water. Use mild cleansers and wash gently (don't scrub).
• Use moisturizers, like lotions, creams, or ointments, to prevent dry skin.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

Syphilis is a sexually transmitted disease caused by bacteria. It infects the genital area, lips, mouth, or anus of both men and women. You usually get syphilis from sexual contact with someone who has it. It can also pass from mother to baby during pregnancy.

The early stage of syphilis usually causes a single, small, painless sore. Sometimes it causes swelling in nearby lymph nodes. If you do not treat it, syphilis usually causes a non-itchy skin rash, often on your hands and feet. Many people do not notice symptoms for years. Symptoms can go away and come back.

The sores caused by syphilis make it easier to get or give someone HIV during sex. If you are pregnant, syphilis can cause complications, or you could lose your baby. In rare cases, syphilis causes serious health problems and even death.

Syphilis is easy to cure with antibiotics if you catch it early. Correct usage of latex condoms greatly reduces, but does not completely eliminate, the risk of catching or spreading syphilis. If your or your partner is allergic to latex, you can use polyurethane condoms. The most reliable way to avoid infection is to not have anal, vaginal, or oral sex.

Centers for Disease Control and Prevention