Trio

Trio Fitting Guide

About Trio Series Multifocals

To help fulfill the needs of the presbyopic generation, BioCurve has created
the Trio Multifocal Series: a series of three bi-asopheric gas permeable multifocals
including a high-add option. This lens is designed for optimum comfort and and
improved visual acuity while providing you with the highest first-fit success
rate.

Lens Description

Trio Series 1 & 2

Both incorporate a Bi-Aspheric design with Trio 1 having a low eccentric value
base curve design and the Trio 2 having a medium eccentric value base curve.
Both incorporate the same aspheric design on the anterior surface.

Trio Series 3 & 3 High-Add

Tri-Aspheric design with a central spherical distance zone in the center
of the lens. The base curve has a bi-aspheric design that incorporates a high
eccentric aspheric curve surrounding the spherical distance zone. This high
aspheric value gives way to a medium eccentric value in order to avoid fitting
a very steep base curve centrally in relation to the flat K.

These designs also incorporate an aspheric design on the anterior surface.
For these designs, the central distance zone can be adjusted to improve either
the distance acuity or the near acuity.

Consultation

For best results, BioCurve recommends you utilize our
professional consultation staff to assist you with selecting the Trio series
lens that is right for your patient. Give our courteous staff your patient’s
SRx and K readings, and we will work with you to design the perfect lens for
your patient.

Available Parameters
Series 1 Series 2 Series 3 Series 3-HA
Base Curve Made to Order Made to Order Made to Order Made to Order
Diameter 9.2mm 9.5mm 9.5mm 9.5mm
Powers +20.00 to -20.00 +20.00 to -20.00 +20.00 to -20.00 +20.00 to -20.00
Thickness 0.8mm from -4.00 and above .12mm from -4.00 and above Standard dimension Standard dimension
Add Power Up to +1.00 +1.00 to +1.75 +1.75 to +2.50 +2.25 to +3.25

Pre-Fitting Examination

Assuming there are no contraindications to fitting, begin by taking
the Keratometer readings. Determine the “Flat K” and amount of corneal
astigmatism (DK).

Choose a BaseCurve

Example: 42.50/44.00 x 180 – Flat K = 42.50 (7.94mm) – DK = 1.50D

Determine the appropriate base curve using the chart below. In the example,
the selected BC = 43.00 (7.85mm) will fit a Trio series 1 design.

Corneal Cylinder, DK Recommended Base Curve
Series 1 0 to 0.87 .25D steeper than flat K
1.00 to 1.87 .50D steeper than flat K
2.00 to 2.62 .75 steeper than flat K
2.75 to 3.25 1.00D steeper than flat K
Over 3.25 Please Call Consultation
Series 2 0 to 0.87 .75D steeper than flat K
1.00 to 1.87 1.00D steeper than flat K
2.00 to 2.62 1.25D steeper than flat K
2.75 to 3.25 1.50D steeper than flat K
Over 3.25 Please Call Consultation
Series 3 0 to 0.87 1.50D steeper than flat K
1.00 to 2.25 1.75D steeper than flat K
2.25 to 2.75 2.00D steeper than flat K
Over 2.75 Please Call Consultation
Series 3 0 to 0.87 1.75D steeper than flat K
High Add 1.00 to 2.25 2.00D steeper than flat K
2.25 to 2.75 2.25D steeper than flat K
Over 2.75 Please Call Consultation

Calculate the Lens Power

To calculate lens power, convert the spectacle Rx to minus cylinder
and adjust for vertex distance. Then compensate for the tear layer
created from the difference of the flat K and the base curve selected.

Spectacle Rx -6.00 +1.50 x 090
Transposition -4.50 -1.50 x 180
Vertex Adjustment -4.25
Tear Lens Compensation -0.50 (from example above)
Contact Lens Rx: -4.75