Contact lenses are small, thin discs made of a transparent material. The outer surfaces are custom-shaped to correct or improve vision and the inner side is carefully formed to fit the surface of the cornea (the clear, front covering of the eye including the iris and pupil). Today, the lenses are typically soft (flexible) but hard (rigid) are still available.
Contact lenses can be a safe and effective way to correct vision for most people. However, people who wear them must follow the directions of their eye specialist - this care includes how long the lenses can be worn continuously, how they should be cleaned and stored, and the good hygiene practices to follow when wearing or handling the lenses.
Many people wear contact lenses because they prefer them to eye glasses - contact lenses do not slip down your nose or fog up in the wintertime. A few people, however, must wear contact lenses to have adequate vision (for example, after cataract surgery, or for medical conditions such as keratoconus - a deformity of the cornea).
Contact lenses can cause some problems that do not produce any symptoms that the contact lens wearer may not notice. For this reason, contact lens wearers should have regular checkups with a specialist who prescribes and fits contact lenses.
Put as simply as possible, the problem is that, according to some people, contact lenses may complicate eye safety.
The arguments against wearing contact lenses in the work environment are based on the following:
However, the opposite may be true as well. Contact lenses may prevent some substances from reaching the eye, and thus minimize or even prevent an injury. Both situations have been documented.
As a result, a wide range of opinions about the safety of contact lenses in the workplace has formed. More complete information is hard to find since occupational injury reporting systems do not typically include information about contact lens use.
The critical point to remember is that contact lenses are not intended to be used as protective devices. They are not a substitute for personal protective equipment (PPE) - if eye and face protection is required for certain work operations then all workers, including contact lens wearers, should wear the proper protective devices. Safe work conditions for all workers are only possible when basic occupational health and safety practices and procedures are followed.
While these conditions may be hazardous to both contact lenses wearers and to people who do not, contact lens wearers should be aware that certain conditions may make it necessary to avoid wearing their lenses. Each situation should be carefully investigated. These situations may include:
In workplaces with ultra-violet and infrared radiation sources, users of contact lenses require protection just as persons not wearing contact lenses do. Contact lens types absorb infrared radiation. This effect is potentially more harmful to the soft lens wearer as it could alter the water balance of the contact lens.
Soft lenses are made from a type of plastic that contains a large proportion of water. The soft lense adheres more tightly to the cornea and does not have as much fluid motion as the hard contact lens. For these reasons, some researchers think the soft lens offers some, but not total, protection against entrapment of foreign substances between the contact lens and the cornea.
The major risks for soft contact lens wearers are from chemical splashes and from hot, dry environments. Because of the high water content of the soft contact lens, some chemicals can pass through the lens and be held against the cornea by the lens itself.
Hot, dry environments can lead to problems because they can cause the tear layer (upon which the lens 'sits') to dehydrate . This situation results in eye discomfort.
Hard lenses are made from an impervious material. Increased risk may result if foreign substances, such as dust or small metal fragments, become trapped behind the contact lens. Since the hard contact lens floats on the tear film in front of the cornea (not in a fixed position), there may be an abrading action between the contact lens and the foreign substance that may result in injury to the cornea. Also, chemicals may become trapped behind the contact lens and held in place against the cornea. In dirty, dusty environments, the wearing of hard lenses may be more hazardous than soft contact lenses.
A contact lens wearer working alone or in a remote area may be at greater risk if hurt with an eye injury. The immediate removal of contact lenses may be important and the injured wearer may be unable to do this. Also, equipment (e.g., eyewash stations) and qualified staff may not be immediately available which, in turn, increases the risk of further damage.
Dislodgement or sudden loss of a contact lens is another problem. The first complication creates sudden changes in vision quality due to decreased visual acuity and blurring. These pose obvious dangers if dislodgement should occur at a moment when sight is essential for safety. The same problems could occur for wearers of glasses though contact lenses may be easier to lose and are more difficult to re-position.
The concern about the use of contact lenses with respirators or personal protective hoods arose because it was believed that dislodgement or sudden loss of a contact lens while wearing a respirator could lead to two potential problems. First, it is impossible to adjust or replace a contact lens while wearing such equipment in a hazardous environment. Secondly, the dislodged contact lens could become trapped in a part of the equipment that prevents its proper functioning.
Most legislation in Canada does not specifically address this question with the exception of British Columbia. In Section 8.38 (Corrective eyewear) of the Occupational Health and Safety Regulation (B.C. Reg. 296/97) part (2) states "The employer may permit the use of contact lenses by a worker who is required to wear a full facepiece respirator if their use is not likely to adversely affect the health or safety of the worker."
The Occupational Safety and Health Administration (OSHA) in the United States has dropped the part of their legislation that banned wearing contact lenses with respirators [Standards 29 CFR 1910.134 (g)(1)(ii)]. OSHA has reviewed recent literature and sponsored several studies and reached the conclusion that there was no evidence that the use of contact lenses with respirators caused an increased risk to the wearer's safety.
It is prudent that a contact lens wearer practice wearing a respirator (with their lenses "in") to see if any problems occur before the respirator is used on a full-time or emergency basis. The OSHA technical manual states "allows the use of contact lenses with respirators where the wearer has successfully worn such lenses before".
The CSA Standard W117.2 states that contact lenses should not be worn by welders and welding personnel. Contact lenses do not provide protection from ultraviolet radiation and flying objects. All workers in proximity to welding procedures must wear appropriate eye protection according to the circumstances.
Reports of contact lenses being "welded" to the cornea (or lens of the eye) as a result of exposure to an arc flash have been proven to be incorrect. It is impossible for contact lenses to become "welded" to the cornea.
Note that in Canada, Prince Edward Island's Occupational Health and Safety Act Regulations (E.C. 180/87) Section 45.11 specifically bans wearing contact lenses while welding.
In Canada, legislation varies from jurisdiction to jurisdiction, and between legislation covering various industrial settings. For the most up-to-date information and for guidance, application or interpretation of these laws or guidelines, you should contact your local jurisdiction directly.
Examples of legislative references include:
Occupational Health and Safety Code (2009),
Section 230 Contact lenses
230. An employer must ensure that, if wearing contact lenses poses a hazard to the worker's eyes during work, the worker is advised of the hazards and the alternatives to wearing contact lenses.
Occupational Health and Safety Regulation (2006)
1.24 The worker as described in 1.22 shall ensure that
(a) the employer is notified when the worker wears contact lenses, has 20/200 vision or less in either eye, or is blind in either eye,
(c) adequate precautions are taken if a hazardous substance or condition may adversely affect the worker when wearing contact lenses,
Mine Health and Safety Regulations
Section 9.27 Injury to Eyes
(2) No person shall wear contact lenses while working at a mine except in areas that the manager has designated, in writing, as an area where contact lenses may be worn.
Newfoundland and Labrador
Occupational Health and Safety Regulations, 2009
Section 77 Contact lenses
77. Adequate precautions shall be taken where a hazardous substance or condition may adversely affect a worker wearing contact lenses
Other guidelines or standards that may apply include:
CSA Z94.3.1-09 Selection, use, and care of protective eyewear
Part 5 Contact Lenses
Can contact lenses be worn in a hazardous workplace environment?
Be aware that contact lenses themselves do not provide eye protection in the industrial sense.
In any environment where industrial eye protection is required, contact lenses should not be worn, except under special medical circumstances (in consultation with a qualified medical professional). If individual medical circumstances require that contact lenses be worn in such environments, eye protection must also be used.
Laboratory Biosafety Guidelines, Canada
3rd Edition 2004
3. Eating, drinking, smoking, storing of either food, personal belongings, or utensils, applying cosmetics, and inserting or removing contact lenses are not permitted in any laboratory; the wearing of contact lenses is permitted only when other forms of corrective eyewear are not suitable; wearing jewelry is not recommended in the laboratory.
To ensure the safe use of contact lenses in the work environment, occupational health and safety principles must be applied to identify and control any possible hazards.
The most common hazards to contact lens wearers have been discussed. Quantification of hazards is difficult and a variety of complex approaches have been developed. However, the most useful way of evaluating the risk is to classify it as either acceptable or not acceptable.
If the risks of wearing contact lenses in a particular environment are found to be within acceptable limits, then the only course of action needed is ongoing monitoring of the situation.
If the risks are found to be unacceptable, then further action is required to eliminate existing hazards or to reduce hazards to acceptable levels.
In any workplace, priority should be to eliminate or control hazards at their source, or control along the path between the source and the worker. When legislation is not specific about implementing particular control measures and procedures, employers still are obliged to take every reasonable precaution to ensure that the workplace is safe.
Many methods are available, and those most applicable to the specific situation should be used. This approach may require the purchase of new equipment, substitution with a non-hazardous substance, isolation of the hazard, addition of safety features to existing equipment, or redesign of the work process. Examples include ventilation; wet or other methods for control of dusty operations; machine guarding; and barriers or screens.
Yes. When the hazard cannot be adequately controlled, personal protective equipment (PPE) may be required. When contact lenses are worn (and where a hazard exists), extra precautions are required to reduce the potential for injury. As previously stated, contact lenses are not protective devices. PPE for contact lens wearers includes splash or dust resistant goggles, and safety glasses. Other workers not wearing contact lenses would wear the same PPE when exposed to the same hazards.
A combination of types of PPE may be necessary if more than one type of hazard exists. For example, where the potential hazards are chemical splashes and flying objects, chemical splash goggles used in combination with safety glasses may be required.
More information about PPE is provided on OSH Answers.
Administrative controls may be used in addition to engineering controls. Administrative controls limit workers' exposures by scheduling reduced work times in contaminant areas or by implementing other such work rules. These control measures have many limitations because the hazard is not removed. Administrative controls are not generally favoured because they can be difficult to implement, maintain and are not reliable.
Where all methods of eliminating and reducing hazards have been explored, and where the PPE cannot adequately protect the contact lens wearer, or where the worker is unable to wear the PPE prescribed, administrative options exist. For example, in some cases, the contact lenses should not be used and eye glasses should be worn used instead. In rare cases, the worker may be offered alternate work.
The employer and the worker have responsibilities to ensure the safe use of contact lenses. Where contact lenses are worn, the following steps should be followed.
An example of guidelines for contact lens use in a chemical environment is available from the National Institute for Occupational Safety and Health (NIOSH) in their document titled Contact Lens Use in a Chemical Environment.
Document last updated on January 18, 2012