Vision Policy: Safety and Savings
There are six vision issues to consider to reduce injuries in the over-40 group.
- By Duane A. Perkinson
- Sep 01, 2009
Vision issues are safety concerns when an employee cannot see his work because of an incorrect prescription, improper lighting, effects of dry eye, or age-related factors. As an eye care professional, I have worked with prescription PPE for the past 30 years and recommended to my clients they establish a comprehensive vision policy for their workforce.
To achieve maximum benefits in safety and savings, your vision policy should address five segments:
- New and current employee prescriptions
- Contact lenses
- Dry eye syndrome
- Workforce above age 40
As safety personnel, you consider many factors to identify and correct hazards that could increase the likelihood an employee will suffer a work-related injury. Among those factors are the individual's biomechanics, the equipment operated, and how the job is executed. But when was the last time you considered how that employee sees his or her work? 20/20 is just a measurement of how clear and sharp (acuity) a letter 1 and 7/8 inches tall, projected on a surface, is when viewed at a distance of 20 feet. Vision encompasses many aspects besides acuity. Vision includes eye teaming and focusing, color perception, ocular pressure, field of view, and internal and external ocular health. Most of us just assume we can depend on our eyes to provide clear, sharp vision, unless our vision starts to fail us.
You have two distinct groups of employees whose vision issues must be addressed.
1. First, for new hires, incorporate a procedure in the hiring process in which the prospective employee presents his current eyeglass/contact lens prescription. The FTC mandates that eye doctors provide a copy of a patient's eyeglass and contact lens prescription at the completion of the vision examination. 1 Your prescription PPE professional should be able to advise you, based on the prescription, whether special visual considerations must be addressed.
2. How do your employees' visual work requirements compare with these numbers:
Standard prescription lens design for seeing at a distance is normally past arm's length (approximately 32 inches). Standard length for reading through a line bifocal is between 16-18 inches, and a line trifocal is set for approximate distances of 18-22/23 inches. Progressive bifocals, depending on the prescription strength, will function between 16 and 24 inches.
Viewing area for clear, sharp vision through a line bifocal is usually between your shoulders, while a progressive bifocal area is in between your ears. To ensure your current employees' safety prescriptions are designed to satisfy the specific working distances2 related to their job, incorporate into your PPE safety program my WIDE vision discovery tool.3 Prescriptions that don't match the job's vision demands may reduce visual accuracy by as much as 38 percent. Employee productivity may decline by as much as 9 percent.
For my clients who utilize WIDE, I see zero safety glass remakes (or cost) due to an incorrect eyeglass prescription. Translated, the employee has received the eyeglass prescription for optimum visual performance. (Please understand with those older than age 40, possibly more than one pair of prescription glasses may be required for an employee to execute all of his job responsibilities.)
Our eyes see very efficiently in full-spectrum light, such as sunlight or incandescent lighting.4 However, when our workplace environment incorporates what is defined as partial-spectrum lighting, our effective visual performance is reduced. Gas discharge lights or fluorescent lights are two examples of partial-spectrum lighting. The simple fact is the photoreceptive cones and rods inside our eyes respond to fullspectrum sunlight, not to partial-spectrum lighting.
Workplace illumination is based on the OSHA regulation 1926.56, Illumination.5 Review foot candle illumination in common areas, stairways, hallways, and after individual assessments.
At age 20, the photopic pupil diameter is 5 mm and the scotopic pupil diameter is 8.0.
Photopic vision is the response of the eye to radiant energy (light). More specifi- cally, this is the response of the cones in the eye to light. Scotopic vision is the response of the rods in the eye to light; scotopic vision is the reception of light that regulates the opening of the pupil of the eye.
Dry, red, irritated eyes—we see them every day. From the computer user to the machine operator and assembler, employees are seeking relief. Dry eye syndrome describes a condition when the eye cannot produce enough tears or tears that are lacking the proper composition. Normal, healthy tears consist of three layers. The layers are often described as an outer oily layer, middle watery layer, and an inner mucus layer. Together, the three layers are necessary for proper lubrication of the eye.
What are the causes of dry eye? During prolonged levels of concentration, such as when you view a monitor, the normal blink rate of 20-30 times per minute drops to about five times per minute. Environmental factors, such as exposure to debris in the work area or outside work open to the wind, and the effects of cold or heat (sweating) may be factors. Other contributing factors include contact with chemicals, certain prescriptions and OTC medications reduce tear volume, and less than six hours of sleep. As we mature, the eye's natural process is to produce lower levels of tear volume.
Treatment options for dry eye conditions can be as simple as applying natural tears when eyes feel dry and uncomfortable.
Aging, Contact Lenses
According to the U.S. Bureau of Labor Statistics, 6 43.3 percent of today's workforce is older than 44. Visual performance is in decline for employees above the age of 40. An employee older than 40 whose prescription does not match his visual task will alter his posture and the distances vital to his job in order for him to see and complete his work. This results in the employee's potentially exposing himself to risk. In some instances, he gets too close to the equipment to see the work. Prolonged upper torso bending and head tipping adversely affect his musculoskeletal health and cause repetitive stress injuries in his back, neck, or shoulders.
I suggest you consider these six vision issues to reduce injuries in the over-40 group:
As of 2003,7 32.4 million American adults wore contact lenses. Employers who permit employees to wear contact lenses in an industrial environment should consider these points. Currently, only one general application OSHA standard is in force specifically addressed contact lenses worn in an industrial environment. This standard8 recommends against contact lens use when working with acrylonitrile, dibromo, chloropropane, ethylene oxide, ethylene chloride, and ethylene dianiline chemicals. Your office should review the work environments in accordance with OSHA's 29 CRF 1910.132 (d) to assess the requirements for protective eyewear.5
- Presbyopia begins in the mid-40s and progresses to a loss of accommodative function by 60.
- Visual acuity is stable up to age 50, then declines.
- A 60-year-old receives only one-third as much light to the retina as does a 20-year-old.
- Pupils become less reactive in low lighting/ contrast conditions.
- Significant dry eye signs and symptoms are prevalent among this age group.
- One in five people older than 65 has impaired vision of 20/60 or less in the better eye.
My recommendation is to use three factors to determine whether contact lenses are inappropriate for any given area in an industrial environment:
1. Does this area already have a documented history of eye injuries and thus pose a potential hazard to the contact lens wearer? Please note: Chemical splashes currently account for 20 percent of eye injuries and flying debris for 70 percent of eye injuries.
2. Does wearing contact lenses place the eye at greater risk of eye injury?
3. Do contact lenses conflict with any existing safety requirement or strategy? Be sure to identify to both employees and visitors any area where the use of contact lenses is prohibited and restricted.
Whether you steer a forklift truck, assemble parts, operate a machine, drive a company vehicle, or use a computer, your eyes are your guiding force. As professionals responsible for employee safety, we shouldn't take for granted employees are seeing as well as they should.
The current OSHA 29 CRF 1910.132(d) hazard assessment checklist for eye protection doesn't address whether there are unique distances for near and/or intermediate lengths necessary for job execution. Nor is the issue of glare protection considered. My recommendation would be to also include an assessment of illumination requirements and safeguard measures against dry eye syndrome. Employers who permit contact lens usage should have a clear, concise contact lens policy in force to guide their business operations and employees. First aid responders with proper training and resources should be capable of safely addressing contact lens issues in the event of an employee injury. An important fact to realize is that in the next seven years, the number of employees who are age 55-64 will increase by 36 percent.9 If your vision policy addresses the five segments I have discussed here, your employees' visual performance will not negatively impact their safety, individual achievement, physical health, or personality. In fact, I believe, just the opposite will occur.
1. The Contact Lens Rule (16 CFR Part 315) and the Eyeglass Rule (16 CFR Part 456).
3. WIDE updated form.
4. "Photopic and Scotopic Vision as Related to Lights" by Bud Wood.
5. OSHA Web site.
6. U.S. Bureau of Labor Statistics Web site from March 2009.
7. Vision Council of America’s 2003 consumer barometer.
8. NIOSH Pub.2005-139, "Contact lens use in a chemical environment CIB 59"
9. “The Personal Touch,” by Theresa Y. Schulz, June 2009 Occupational Health & Safety, pp. 49-51.
This article originally appeared in the September 2009 issue of Occupational Health & Safety.