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EZ MULTIFOCAL FITTING GUIDE

EZ Multifocals are poly-aspheric in design and offer between 1.00D - 2.25D of available add power. Our unique manufacturing capabilities allow for an ultra thin edge profile which provides excellent comfort. In addition, EZ Multifocals have the ability to move across the cornea, which creates the added dimension of translation. This feature makes it easier to deliver sharp vision at both distance and near.

Base Curve Selection

Follow the appropriate fitting nomogram below for low to high add requirements. The standard diameter for EZ Multifocals are 9.5, however any diameter can be requested. The base curve is selected slightly steeper than the central keratometry reading. This allows the mid-periphery of the lens to align with the cornea, resulting in a relatively central and stable fit.

EZ.1 Multifocal™
up to 1.75D of Add

Corneal Cylinder        Steepen Flat "K" by

0.00D to 2.00D                     1.50D

2.12D to 3.00D                     1.75D

3.12D and above Use a bitoric design

EZ.2 Multifocal™
up to 2.25D of Add

Corneal Cylinder      Steepen Flat "K" by

0.00D to 2.00D                       2.00D

2.12D to 3.00D                       2.25D

3.12 and above Use a bitoric design

Lens Position

Upon evaluation, the lens should be central to slightly superior in primary gaze. This will allow the patient to view through the most minus central portion of the lens. A slight decentration upward will also allow the patient to view through the intermediate zone, providing simultaneous vision. A lens that is decentered excessively will cause the patient to view through the intermediate and near zones. Improve poorly centered lenses by steepening the base curve or increasing lens diameter. Lenses that center after the blink but are not held by the upper lid very well can be flattened or enlarged to improve lid attachment.

Lens Movement On Blink

Once good lens positioning is attained, evaluate movement on blink. Movement on blink should be smooth and efficient where the lens glides vertically after the blink to produce good tear pumping. But the lens should return to its primary position relatively quickly so that distance vision is not disturbed between blinks. Too little movement indicates too steep a fit, and a flatter base curve should be tried even if the lens centers well. Excessive movement, especially laterally, indicates too flat a fit, and a steeper base curve should be tried.

Translation on Down Gaze

Ask the patient to look down and lift the upper lid to observe the lens position. The upper edge of the lens should be at or above the superior limbus. This indicates that the lens can move freely upward, and that translation is occurring on down gaze. Poor translation can be improved by flattening the base curve or decreasing lens diameter. The patient should also be taught to look downward when reading or performing other near tasks to maximize near vision.

Fluorescein Pattern

Once you attain ideal lens position and movement, use the fluorescein pattern to confirm the fitting relationship and to predict any potential complications. Ideally, you will see slight apical clearance, mid-peripheral alignment and a moderate to wide band of peripheral clearance.

Visual Assessment

Use loose lenses to perform binocular over-refractions, and the highest plus power should be determined for distance. The same over-refraction lenses should then be used to check near acuity. Make sure the patient looks down during the near over-refraction to ensure they are looking through the most plus portion of the lens.