Eye and Vision disorders

Blindness. This is the loss of useful sight. Blindness can be temporary or permanent and it has many causes. Birth defects or damage to any portion of the eye, the optic nerve, or the area of the brain responsible for vision can lead to blindness. The visual impairment cannot be corrected with surgery or corrective lenses, and the condition can make it difficult to perform everyday activities.

Cataracts. Some children are born with cataracts, a cloudiness of the eye's lenses that prevent images from being seen clearly or at all. But cataracts are much more prevalent in the elderly among whom surgery to remove cataracts and correct vision is common.

Colour blindness. Colour blindness is caused by problems in the pigments of the cones in the retina. Most people who are colour-blind can see some colours. In most cases, someone who is colour-blind confuses some colours with others, usually red and green. People can be born colour-blind or they may develop the condition over time. The most common form of colour blindness is an inherited condition that affects boys much more often than girls. Colour blindness cannot be corrected.

Conjunctivitis. Conjunctivitis refers to inflammation (redness, pain, and swelling) of the conjunctiva. One type of conjunctivitis is called pinkeye, a common contagious infection in which the eyes become pinkish red and watery, and pus may form. Pinkeye is usually treated with eye drops. Conjunctivitis may also occur due to allergies or from a scratch on the surface of the eye.

Eye injuries. Injuries to the eye are one of the most common preventable causes of blindness. Eye injuries may be caused by irritants such as sand, dirt, or other foreign bodies on the eye's surface. Chemicals or foreign bodies that become embedded in the eye can also cause pain and loss of vision. Forceful blows to the eye can cause bleeding inside the eye and damage to the cornea, retina, and other important eye structures.

Glaucoma. One of the leading causes of blindness, glaucoma, is a disorder that causes fluid pressure to build up inside the eye, potentially causing damage to the optic nerve. Although it can occur in infants and children, it is much more common among older adults.

Macular degeneration is an eye disease that mainly affects older people. But sometimes infants and children can develop it, too. When someone has macular degeneration, the middle area of the retina becomes scarred. This causes eyesight to deteriorate over many years. The cause of macular degeneration is unknown in most cases, but it tends to run in families, which indicates that genes and heredity are involved.

Strabismus. A condition in which the eyes appear crossed, strabismus is usually caused by a defect in the balance of the pull exerted by the muscles that help the eyes stay straight and move together properly. Surgery on the eye muscles can help realign the eyes. Permanent vision loss in the less-used eye can occur if the condition is not treated in early childhood.

Sty. A sty is an infection of one of the follicles from which the eyelashes grow. Sties are treated by applying warm compresses and using antibiotics.

Ear diseases

Ear disease is a subfield of otolaryngology addressing the pathology of the ear.

There are many different types of ear problems. For example, ear pain may be caused by infections of the tonsils, jaw or sinuses. Chronic infection, for example, glue ear, can cause hearing loss that can affect learning and lifestyle, and exposure to loud noise can also damage hearing. As well as infection, the ears can also suffer from dermatitis reactions to topical medicines, wearing jewellery, cosmetics or methacrylate ear plugs.

Otitis media is inflammation of the middle ear, causing a build-up of fluid, with or without an infection. If there is an infection, it is often viral. Many children will have several bouts of otitis media before they are 7 years old. Symptoms include crying, ear pulling, mild fever and irritability.

Glue ear is a type of chronic otitis media. Long term build-up of thick or 'sticky' fluid in the middle ear, behind the eardrum, causes hearing loss. This makes socializing and learning very difficult, especially if hearing loss is not recognized in early childhood.

Ear wax in the ear is normal and protects the ear. However, a build-up of wax may be a problem in some adults. This may require wax-softening ear drops, and sometimes the ears may also need to be syringed clean by a doctor. Impacted ear wax rarely causes an ear discharge or pain, but it may cause hearing impairment.

Swimmer's ear develops when humidity, heat and moisture cause the skin layer inside the ear to swell. The addition of further water, for example, through swimming, makes the skin lining the ear canal even softer and liable to infection. Attempts to remove the water with cotton buds or other objects may make the condition worse, causing pain and itching.

The word "vertigo" means the kind of giddiness in which things actually seem to spin round you. It is often due to problems in the balance mechanisms of the inner part of the ear. Possible causes include labyrinthitis and Meniere's disease. There is also something called "Benign Positional Vertigo", which often develops in the second half of life. What happens is that you move your head - and then you suddenly feel awfully giddy. The cause is believed to be tiny "stones" in the fluid of the inner part of your ear. Fortunately, surgeons have developed a way of curing the condition by carrying out a manipulation called "Particle Reposition Manoeuvre".

Catarrh in the back of the throat is notorious for causing all sorts of symptoms in the ears; deafness, "popping", discomfort and sometimes slight giddiness. The commonest cause is smoking. Catarrh can't be treated with ear drops -because they wouldn't get through the ear drum. So the most common way of treating it is with nose drops.