A sty (sometimes spelled stye) is a tender, painful red bump located at the base of an eyelash or on, inside, or under the eyelid. A sty is caused by an infection of a clogged oil gland in the eyelid. A sty can also be caused by an infected hair follicle at the base of an eyelash.

The proper medical term for a sty is hordeolum. An external hordeolum refers to a sty that develops at the base of an eyelash involving a hair follicle of the eyelid, and a internal hordeolum refers to a sty caused by clogged glands in the eyelid. Nearly all styes, approximately 95%, are caused by the bacterium Staphylococcus aureus.

Styes will usually enlarge over several days as the infected follicle fills with pus, but most of the time it will clear up in three to seven days. The bump should not be squeezed, since this action could spread the infection and cause other styes to form.

Styes are not a serious health risk, and they do not affect vision. Although styes often recur they usually respond well to self-treatment.

Self-treatment of styes consists of applying a hot compress for 10 minutes three to four times a day. This effort may decrease pain and the stye may clear itself up. If there is no improvement after 48 hours of home treatment, a visit to the doctor my be advised and the stye may be opened and drained under sterile conditions. An antibiotic ointment or eyedrops for topical use on the eye may be prescribed.

Astigmatism is another common eye condition that affects many people. Astigmatism can be easily corrected by eyeglasses, contact lenses or surgery.

An astigmatism is an irregular curvature of the cornea. In astigmatism, the cornea is shaped more like a football, an oval shape, than the normal round shape like a baseball. This irregular shape causes two images to be focused. This type of disorder is also known as a refractive error. Nearly everyone has astigmatism to some degree. Astigmatism is usually present since birth and generally worsens as we get older. Some common causes of astigmatism are pressure from the eyelids on the cornea, incorrect posture or an increased use of the eyes for close work.

Common symptoms of astigmatism are headaches, fatigue, eyestrain and blurred vision at all distances. While these symptoms may not necessarily be the result of astigmatism, you should schedule an eye exam if you are experiencing one or more symptoms.

Treatment for astigmatism includes eyeglasses, special contacts, and certain refractive surgeries. Special contacts called toric can be specially designed for people with astigmatism. Minor degrees of astigmatism can be corrected with soft toric lenses. More serious cases of astigmatism are better corrected with eyeglasses or RGP toric contact lenses. Toric contact lenses are more expensive than normal contacts because of the extra correction provided on them.

Surgical treatments for astigmatism include LASIK Eye Surgery (Laser in-situ keratomileusis) and CK (Conductive keratoplasty) for people over 40, Astigmatic Keratotomy (AK), and Orthokeratology. LASIK reshapes the cornea by removing tissue. In Astigmatic Keratotomy, a surgeon places incisions in the periphery of the cornea to change its shape for better vision. Orthokeratology, or Ortho-K, uses RGP contact lenses to gradually reshape the cornea. The reshaping of the cornea is not permanent however and the special contact lenses will still be worn a few hours a day to keep the new shape. Only minor degrees of astigmatism are best treated with this method. There is ongoing research to develop better and more advanced methods of correction of astigmatism. New advances in materials and technology will greatly help people with astigmatism see clearly again.