How could two little pieces of plastic be too dangerous for a school science lab or any laboratory for that matter? Well, those two little pieces of plastic (depending on the type) may do more than clear up your vision. They may subject the wearer to severe eye injuries when they interact with select chemicals. So are contact lenses too dangerous? Let’s find out.
When contact lens were first developed they were known as “hard” lens partly because of the material but also because they did not allow oxygen to pass through the material into the cornea. Newer “soft” lens allow more oxygen to pass through to the cornea. They also allow other chemicals to pass through to the cornea which is where the trouble begins.
Not only do contact lenses allow oxygen and other chemicals to pass through the lens onto the cornea itself, they can also trap chemicals, liquids, dust, and other particles under the lens through a process known as “capillary action.” This can make it difficult for contact lens to be removed in the event of exposure to a liquid/chemical. Which is vital in an emergency situation. It can also make chemical absorption much quicker thereby posing a higher health-hazard risk to the student. In some cases, contact lenses may melt onto the cornea when exposed to certain chemicals which could lead to irreparable damage to the wearer’s eye.
Since 1978 NIOSH, The National Institute of Occupational Safety and Health, has recommended that workers not wear contact lenses when working with chemicals or while performing other hot work (welding) to protect themselves from the above hazards. This year, as Science Chairs and Chemical Hygiene Officers explore the California Science Safety Handbook (read more) are finding that the handbooks specifically addresses the use of contact lenses in school science labs on page 47. Why this year? The Handbook was finally updated in mid to late 2012 and it’s release if finally make its way through schools.
While most school sites have a policy against student use of contact lenses during science/chemistry courses, many do not. If your school decides that it wants to allow the use of contact lenses, then special provisions should be made in your chemical hygiene plan and your staff training programs. Special goggles should be purchased and students should be inspected for utilization of proper safety PPE prior to starting any experiment. The best way to reduce your risk, of course, is to prohibit the use of contact lens in your science classrooms.