Help is on the way for those headaches, blurred vision, tired eyes, and neck pains for adults and kids that spend more than 2 hours in front of a computer.

What’s the Problem?
The problem is constant focus at mid-range that taxes the eye and incorrect eyeglass power or design.

Technically, the eye needs +2.50 diopters to read at 16 inches (40cm) i.e., if D =100/f(cm) then the power D = 100/40 or +2.50 diopters. A +1.50D add wearer uses +2.50D to read at 16 inches; they get +1.50 from their add and use +1.00D of the eye’s reserve of accommodation. At twice the distance, this patient would use half the add (+0.75D). Their +1.00D accommodative reserve can provide clear vision through the distance portion of their lenses for mid-range vision.

A +1.75D add wearer gets +1.75 from the add, +0.75D from the eye’s reserve. A monitor at twice the distance requires +0.87D and with only +0.75D of comfortable reserve, they cannot see clearly at mid-range and require an intermediate. In progressives, the corridor continues to narrow as add power increases or are shortened. Prio Corporation also points out that the “Characters on a computer are brightest at their centers and diminish in intensity toward their edges. Our eyes are unable to maintain focus and… instead drift out to a point called the resting point of accommodation (RPA)”. So the solution is computer lenses specially designed and powered for the job.

The Monitor and Workspace
First, tell patients to place the computer screen 4-8 inches below the line of sight for the most comfortable “eye and head posture”. This helps with neck and backaches since this is the head and eye’s resting position. Think laptop for the right position.

Less Plus Power
 Computer lenses are reading lenses that lose plus power (range or degression), as the wearer raises their eyes. A +2.00D add at 16” is only +1.00 at 32”. Therefore, choose the range of a patient’s computer lens by first knowing how far a monitor and other important materials are located from their glasses. The higher the add and/or the farther away clear vision is required, the higher the range needs to be.

{Sponsored by Essilor of America and Luxottica Group}
www.varilux.com • www.crizalpro.com • www.luxottica.com