Eye injuries account for some 2–3% of all injuries of the human body and are most often due to the direct or indirect effect of foreign bodies, liquids, or gases on the eye, usually as the result of an accident. Such injuries are about equally frequent in persons who wear contact lenses, spectacles, or neither.

Emergency visits to the general ophthalmologist or to the contactologist are usually due to foreign-body or chemical injuries. Relatively efficient protection against injuries of these types is afforded by spectacles, even better protection by goggles that are worn in the work-place where there would otherwise be a risk of eye injury. The contact lens wearer, however, cannot benefit from the protective function of spectacles, and all too often disregards medical advice to wear protective goggles in those situations where they are indicated.

Unlike spectacles or goggles, contact lenses do not protect the eyes against metallic shards expelled in projectile fashion from lathes, grinders, planing machines, or other types of apparatus. Slit-lamp examination reveals the shards embedded in the contact lens as well as in areas of the conjunctiva and cornea not covered by it.

Glowing hot shards from welding can become embedded in the matrix of the lens, leaving visible tracks; they can even pierce soft lenses. Metallic particles embedded in a hydrophilic contact lens may rust and render the lens unwearable.

Just as dangerous are wooden splinters ejected from grinders, lathes, circular saws, and milling machines. These organic splinters often serve as a vehicle for bacteria and fungi that can attack both the eye and the contact lens.

Explosives and firecrackers may cause irreversible eye injury, driving tiny bits of shrapnel into the lids, conjunctiva, cornea, and contact lens. Destruction of the lens surface is easily seen under the slit lamp or microscope. Lenses damaged in this way are unwearable, among other reasons because the foreign material embedded in them can chemically irritate the lids, conjunctiva, and cornea and cause further injury.

Open-globe injuries in contact lens wearers are often caused by fragments of a shattered windshield when the patient has been the unrestrained driver, or front-seat passenger, in an automobile accident. Such injuries can be very severe; on occasion, the contact lens must be surgically removed from the interior of the eye along with the glass shards. Goggles worn at the workplace do not afford 100% protection: We have seen a case in which a steel rod propelled from a machinist’s lathe shattered his goggles, creating glass shards that destroyed his contact lens (worn because of aphakia) and simultaneously perforated the globe.

Blunt trauma poses particular dangers for contact lens wearers. As an example, patients who wear spectacles can be injured by a flying tennis or squash ball only if its momentum is sufficient to shatter the spectacles and drive the shards into the eye. Contact lens wearers, however, lack the degree of protection that spectacles afford. If the flying object impacts against the contact lens or the globe, hemorrhage can result; in rare cases, the contact lens is shattered.

We have seen a case in which a flying champagne cork directly impacted against a rigid contact lens, not shattering it, but deforming it so that it had to be replaced. In fact, contact lenses must be replaced whenever they are damaged by contact with a foreign body, even if the damage is small and confined to the edge of the lens. Tiny edge defects can cause ring-shaped conjunctival hemorrhage or circular corneal erosions if the lens continues to be worn. Moreover, such lenses, if worn, can produce pseudoherpetic corneal epithelial defects that are very difficult to distinguish from dendritic keratitis. If this situation should arise, the correct diagnosis can be made by careful inspection of the posterior surface of the lens.

Symptoms: Exogenous toxic chemicals induce marked acute conjunctival injection and chemosis, as well as corneal swelling. Other symptoms are pain and lid spasms that become more severe when the contact lenses are removed.

Clinical findings: Chemical injuries produce the same symptoms and have the same sequelae in contact lens wearers as in persons who do not wear contact lenses.

Not only solid foreign bodies, but also liquids splashed into the eye can damage the eye and contact lens. Now and again, contact lens wearers, mistakenly thinking that they are wearing spectacles, spray an eyeglass-cleaning solution directly into a contact-lens-bearing eye. Hard lenses are rarely damaged in such incidents, but soft lenses may store the detergent chemicals in the cleaning solution and later re-release them into the eye, causing severe irritation. Thus, whenever eyeglass-cleaning solution is sprayed onto a contact lens, the lens should be discarded.

We have encountered another case in which inadvertent switching of cosmetics resulted in the application of fingernail polish containing silver particles to the eyelids. Some of the silver particles found their way onto the conjunctiva, cornea, and contact lens, destroying the lens.

Accidents with gaseous substances occur in the workplace and elsewhere. Many water-soluble gases can be taken up by contact lenses and then severely irritate the eye when they are re-released during contact lens wear; examples include tear gas, CS gas, and pepper spray. Firemen are often exposed to chemical fumes that can be taken up by soft lenses, causing discoloration and deformation of the lens and deposition on its surface. Contact lenses that have been involved in such incidents should be destroyed.

Peroxide injuries are, unfortunately, common in contact lens wearers. They are usually the result of inadvertent switching of solutions, so that the lens is stored in the neutralizing solution and then rinsed in hydrogen peroxide. A contributory cause of such accidents is inadequate instruction of the patient regarding the use of lens hygiene products and the dangers of misuse. This only underscores the need for thorough patient instruction.

Any cut, burn, or chemical injury to the eye of a contact lens wearer requires immediate ophthalmological examination and treatment. The contact lens should be removed at once and its inner and outer surfaces inspected under the microscope. The eye must be carefully examined to assess the nature and extent of injury. Fluorescein staining should be performed to detect any possible epithelial injury.