Fuchs' dystrophy is the most common type of corneal dystrophy, affecting approximately 1 in 200 people. It is characterized by the accumulation of abnormal deposits in the cornea, which can lead to vision problems.

Trachoma is the leading cause of corneal blindness worldwide, affecting an estimated 1.9 million people. It is a chronic infectious disease caused by the bacterium Chlamydia trachomatis, which is spread through contact with infected eyes or contaminated objects.

Keratoconus is a condition in which the cornea becomes progressively thinner and weaker, causing it to bulge outward. This can lead to significant vision problems, including blurred vision, double vision, and astigmatism.

Corneal collagen cross-linking is a surgical procedure used to strengthen the cornea and prevent further progression of keratoconus. It involves the use of ultraviolet light and a photosensitizing agent to create new cross-links between the collagen fibers in the cornea.

Bacterial corneal ulcers are the most common type of corneal ulcer, accounting for approximately 70% of all cases. They are typically caused by bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus pneumoniae.

The treatment for a corneal ulcer depends on the underlying cause. Bacterial corneal ulcers are treated with antibiotics, fungal corneal ulcers are treated with antifungal medications, and viral corneal ulcers are treated with antiviral medications.

Corneal opacity is a condition in which the cornea becomes cloudy or opaque, which can lead to vision problems. It can be caused by a variety of factors, including infection, injury, and genetic disorders.

Corneal transplant is the surgical procedure used to remove a corneal opacity and restore vision. It involves replacing the damaged cornea with a healthy donor cornea.

Keratitis is a condition in which the cornea becomes inflamed. It can be caused by a variety of factors, including infection, injury, and autoimmune disorders.

The treatment for keratitis depends on the underlying cause. Bacterial keratitis is treated with antibiotics, fungal keratitis is treated with antifungal medications, and viral keratitis is treated with antiviral medications. Steroid eye drops may also be used to reduce inflammation.

Astigmatism is a condition in which the cornea is abnormally curved, causing light to be focused unevenly on the retina. This can lead to blurred vision, double vision, and eye strain.

Astigmatism can be corrected with eyeglasses, contact lenses, or refractive surgery such as LASIK or PRK.

Keratoconus, pellucid marginal degeneration, Terrien marginal degeneration, and corneal ectasia are all conditions in which the cornea is abnormally thin.

The treatment for corneal thinning depends on the underlying cause. Keratoconus and pellucid marginal degeneration can be treated with corneal collagen cross-linking, corneal transplants, or Intacs. Terrien marginal degeneration and corneal ectasia may require corneal transplants.

Corneal edema is a condition in which the cornea is abnormally thick due to the accumulation of fluid. It can be caused by a variety of factors, including infection, injury, and genetic disorders.

The treatment for corneal edema depends on the underlying cause. Diuretics and hypertonic saline eye drops can be used to reduce fluid accumulation in the cornea. Corneal transplants may be necessary in severe cases. Laser surgery may also be used to improve vision in some cases.