Fitting Pearls

• Evaluate tear film, pupil size and lower lid position
• Use diagnostic lenses
• Have available at least one aspheric and segmented diagnostic set
• Go to www.gpli.info for a complete list of CLMA member labs and their multifocal products
• Use trial lenses for over-refraction
• Evaluate the position of segmented designs to the lower lid
• Segment line should be at or near the lower pupil margin
• To evaluate the reading portion of a segmented design, lift up the lid as the patient looks down: the lens should be pushed up. This is referred to as translation.
• Some nasal rotation can be beneficial for reading
• High eccentricity aspheric lenses are usually fit up to 3D - 4D steeper than K
• Low eccentricity aspheric lenses are usually fit up to 1D - 2D steeper than K
• Aspheric lenses typically require good centration with minimal lag on blink (1mm)
• Some aspheric designs benefit from the lens positioning under the upper lid
• Aspheric multifocals benefit from some lens translation when patient looks down to read
• Use the CLMA lab consultants for fitting advice

Making Lens Design Changes

To improve the fitting relationship, make a significant change in lens design:

• Change BCR at least 0.50D
• Change diameter at least 0.3mm
• Change amount of prism at least 0.50D
• Consider switching lens design concepts if unsuccessful with one style

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