Corneal Ulcer Causes

• Most corneal ulcers are caused by infections.

• Bacterial infections cause corneal ulcers and are common in people who wear contact lenses.

• Viral infections are also possible causes of corneal ulcers. Such viruses include the herpes simplex virus (the virus that causes cold sores) or the varicella virus (the virus that causes chickenpox and shingles).

• Fungal infections can cause corneal ulcers and may develop with improper care of contact lenses or the overuse of eyedrops that contain steroids.

• Tiny tears to the corneal surface may become infected and lead to corneal ulcers. These tears can come from direct trauma by scratches or metallic or glass particles striking the cornea. Such injuries damage the corneal surface and make it easier for bacteria to invade and cause a corneal ulcer.

• Disorders that cause dry eyes can leave your eye without the germ-fighting protection of tears and cause ulcers.

• Disorders that affect the eyelid and prevent your eye from closing completely, such as Bell's palsy, can dry your cornea and make it more vulnerable to ulcers.

• Any condition which causes loss of sensation of the corneal surface may increase the risk of corneal ulceration.

• Chemical burns or other caustic (damaging) solution splashes can injure the cornea and lead to corneal ulceration.

• People who wear contact lenses are at an increased risk of corneal ulcers. The risk of corneal ulcerations increases tenfold when using extended-wear soft contact lenses. Extended-wear contact lenses refer to those contact lenses that are worn for several days without removing them at night. Contact lenses may damage your cornea in many ways:

• Scratches on the edge of your contact lens can scrape the cornea's surface and make it more vulnerable to bacterial infections.
  
  
• Similarly, tiny particles of dirt trapped underneath the contact lens can scratch the cornea.
  
  
• Bacteria may be on the improperly cleaned lens and get trapped on the undersurface of the lens. If your lenses are left in your eyes for long periods of time, these bacteria can multiply and cause damage to the cornea.
  
  
• Wearing lenses for extended periods of time can also block oxygen to the cornea, making it more susceptible to infections.