Merchant Processing Services

What is Computer Vision Syndrome?

Computer Vision Syndrome (CVS) was first described by OSHA in 1999 as, “a complex series of eye and vision problems that are experienced during and related to computer use.” Affecting up to 90% of the workforce in the United States, CVS is complicated and often under diagnosed because many of its symptoms are universal to other vision related problems. These symptoms include dry eyes, blurred vision, headaches, and difficulty changing focus from near and distance.

These symptoms occur for a number of reasons. One, the human eye is designed to focus on clear, solid images. The computer screen however, utilizes pixel images. Pixels are dots that are arranged to form an image. Because of this, the eye works harder to make the image appear solid when interpreted by the brain. Also, the eye is designed to maintain focus on far away objects for long periods of time more easily than near images. 

Determining if it’s CVS

To help determine when the symptoms are related to computer use or related to another problem, it is helpful to provide the patient with a questionnaire. Some questions that should be asked are:

• Do you have dry, tired, or sore eyes?

• Do you have headaches while on the computer? Shortly after?

• Do you need to interrupt work frequently to rest your eyes while on the computer?

• Is driving or night vision worse after working on a computer?

• Does squinting help when looking at the computer?

• Do you have body fatigue or pain in the neck, shoulders, or back?

• How often are you on the computer a day?

If the patient answers yes to a majority of these questions or works on the computer for longer than three hours a day, then the patient is likely suffering from CVS and needs treatment.

Computer Lenses

One of the easiest ways to treat CVS is to provide the patient with computer lenses. By providing glasses formulated just for computer distance, accommodation relaxes, eyestrain and blurred vision is reduced, and the patient can maintain a more natural posture which decreases the amount of pain in the neck, back and shoulders. This results in the patient’s work productivity and accuracy increasing. There is a wide range of options available to the ECP and patient to help with computer use.

Intermediate only single vision

This computer lens is designed to have only the prescription for computer distance throughout the whole lens. Computer distance, also known as intermediate distance, is typically 20 to 26 inches away. It is important for the ECP to know how to convert a prescription into an intermediate prescription if the prescriber has not provided one to the patient. Use the following prescription for an example. 

OD -2.00 -1.00 x 180
OS -2.50 sphere
1.50 add power

Step 1 - determine the intermediate power. To do this, 50% of the add power is added to the sphere power of the distance prescription. 

OD +0.75 + -2.00 = -1.25
OS +0.75 + -2.50 = -1.75

Step 2 - leave the cylinder and axis the same.

OD -1.25 -1.00 x 180
OS -1.75 sphere

This will provide the final intermediate prescription to use in a single vision lens. The benefits are the widest intermediate area possible with no image jump or possibly distracting lines. The main drawback is the lack of a near area. This can be a serious problem because many who work on a computer usually have to look at a near distance also.

Occupational lined bifocal

A modified flat top is a very popular method of treatment for CVS. The portion of the lens that is usually reserved for distance is modified for intermediate use and the bifocal portion remains for near use. To do this, the ECP must perform an additional step to the previous example. The ECP must create a new add power that is 50% of the original add power. This is important; otherwise the near power will be too strong. The final modified Rx will be:

OD -1.25 -1.00 x 180
OS -1.75 sphere
0.75 add power

Although all bifocal widths can be used, the flat top 35 is usually the most effective choice. The benefits to using a flat top 35 are very wide, useable areas, the least amount of distortion, and two powers in one lens. The drawback is a line that some patients will find unflattering.

Customized Occupational Progressives

Since presbyopic computer users are growing at an exponential rate, many lens companies have developed progressives just for computer use. Customarily designed for distances of 12 to 48 inches, these lenses offer numerous benefits to the fashion conscious patient. The distracting line is removed, image jump is eliminated, and the patient may already be accustomed to progressives in their dress wear. Some of the best occupational progressives on the market today are:

• Shamir- Shamir uses what they term “Eyepoint Technology” to create a line of lenses for a small range area called Office. A way of utilizing free form manufacturing techniques, Eyepoint Technology creates a wide, edge to edge, clear visual path from the intermediate to near areas.
  

• Zeiss- Carl Zeiss Vision manufactures lenses under the Zeiss and Sola names. The two lines marketed under the Zeiss name are the Gradal RD and Zeiss Business. The Gradal RD is designed a little differently than other computer lenses. Instead of being developed for a distance of approximately 4 feet or less, the Gradal RD is developed for what the company calls “room distance” or 10 feet. It provides clear vision for all indoor activities and eliminates the head bobbing that commonly occurs with traditional progressives.

The Zeiss Business lens is designed for distances up to 4 feet and is available in short corridors to allow a wider range of frame choices. The Sola Access lens is designed for distances up to 7 feet. It has an extremely wide near area as well as a wider intermediate area than a traditional progressive. The intermediate width however is dependent upon the strength of the prescription.

• Essilor- Essilor USA has recently announced a computer lens that is designed to address visual fatigue. Named the Essilor Computer lens, it will offer a larger full distance power than any other computer lens. In addition, it has a larger intermediate and near area to create a more ergonomic environment for visual tasks.

Anti-Reflective Lens Treatment

Florescent lighting and computers all cause an increase of reflections in the workplace. This increase in reflections causes eyestrain, headaches, fatigue and a decrease in work productivity. By combining the AR coating with a specialty computer lens, the ECP is providing the best possible solution to CVS.

Computer Vision Syndrome is a serious problem in the United States and will only get worse as computer use increases and the population ages. The ECP can help the patient feel better, reduce stress and muscle fatigue, increase productivity, and improve vision all by recommending the correct product for the patient’s needs. Computer lenses are an excellent way to help the patient and increase second pair sales. 

Carrie Wilson
BS, LDO, ABOAC, NCLEC