Multifocal Myths Debunked: Myth #6

Multifocal Myths Debunked: Myth #6

MYTH #6: Many fitters believe that decreasing the minus power in the distance zone of the (N) lens will solve near vision complaints with the ProClear Multifocal.

FACT: Near vision concerns can be in either the (D) lens or the (N) lens. The only way to know which lens and which zone to adjust is to check each lens independently at both distance and near.

In myth #5, I presented a method for problem solving distance vision issues with the ProClear Multifocal. The process for near problems is exactly the same but pays attention to the near vision specifically. First, check binocular acuity. Then monocularly verify performance with each eye. Let’s look at an example:

Patient BY has an Rx of, OD -2.00 ADD +2.00  Dom VA 20/20   J-2

                                         OS -2.25 ADD +2.00            VA 20/20   J-2 

ProClear Multifocal lens Rx,           OD -2.00  ADD  +2.00 (D)    VA  (OU)   20/20   J-4 

                                                         OS -2.25  ADD  +2.00 (N)

The patient complains of poor near vision. 

Monocular VA                OD  20/20    J- 5       over refraction  +0.25 =  20/20   J-3

                                        OS  20/30    J- 2       over refraction   plano = 20/30   J-2 

New OD lens                   OD -1.75   ADD  +2.00 (D)

Binocular VA                   OU 20/20  J-2 

 In this case the (N) lens is fine, however, the (D) lens is failing to perform as well as expected at near. The seemingly small, +0.25 over refraction in the (D) lens brings the OD to a better balance and eliminates the slight near concern. It is important to be sure to minimize minus (-) in the spec Rx for both eyes.

Here is a quick reference point for the fitter in regards to visual expectations as the ADD power goes up:

ADD D Lens

Distance VA

Near VA

ADD N Lens

Distance VA

Near VA

+1.00

20/20

J-2

+1.00

20/20

J-2

+1.50

20/20

J-3

+1.50

20/25

J-2

+2.00

20/20

J-3

+2.00

20/30

J-2

+2.50

20/20

J-4

+2.50

20/40

J-2

 

When we think about chair time, we may want to consider products that afford us the simplest path to success. A product like ProClear Multifocal puts optical designs in place that will optimize your opportunity to be successful. Each patient has individual needs and ProClear will allow you to fine tune the vision to meet those needs.

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