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# FITTING STEPS

### EASY CALCULATION

• Effectiveness is related to “Target Power” and “Shape of cornea”.

• Generally, the higher the Target power is, the less effective it is.

• Our recommended way to judge applicability is the calculation formula:

(Flatter meridian) - (Target power)  ≧ 39.00

For example, if the Flatter meridian is 44.00 D, target power under -5.00 D

### ESTIMATION FROM TOPOGRAPHY PATTERN

Applicable eyes that lens can be positioned in the center of the cornea

### ESTIMATION FROM TOPOGRAPHY PATTERN

Non-applicable eyes that cannot be well- centered

#### DETERMINE THE 'FITTING CURVE' REFERRING  TO AVERAGE OF KRT DATA

Fitting Curve ≒ AVG K (45.00)
Target Power  = ?
Diameter = 10.6 (Standard Size)

#### CALCULATE THE DIFFERENT OF THE FITTING CURVE & THE FLATTER MERIDIAN

Target Power ≒ S + (Flat K-Fit Curve)

Referring to KRT data:

Target Power  =-4.50+(44.25-45.00) = -5.25

Final Target Power = -5.50*

*Adjusted by measuring the refractive power while wearing the lens.

1st Choice Trial lens as follow :

Fitting Curve (FC) = 45.00

Target Power (TP) = -5.50D

Diameter (D) = 10.6mm

### POSSIBLE RANGE TO ORDER

Fitting Curve Range

39.00D ~ 47.00D

Target Power

-1.00D ~-8.00D

Lens Diameter

10.2 mm

10.6 mm [Standard Diameter]

11.0 mm

#### STEP 3 : JUDGEMENT

• Criteria for the fitting condition after 15 minutes of lens wear

• Lens is proper centered.

• Lens move 1~2 mm at blinking.

• A proper doughnut pattern is achieved, and also the optical zone as wide as 3 mm.

• Vision correction needed by patient should be obtained and stable, and wearing feeling is comfortable.

### GOOD FITTING

1. Criteria for fitting condition after 15 minutes of lens wear

2. Lens is proper centered.

3. Lens move 1~2 mm at blinking.

4. A proper doughnut pattern is achieved, and also the optical zone as wide as 3 mm.

5. Vision correction needed by patient should be obtained and stable, and wearing feeling is comfortable.

### TIGHT FITTING

• narrow optical zone

• less moving

• insufficient tear exchange

### LOOSE FITTING

• the lower edge of the lens has clearance from the cornea

• Loose moving

• tear pass through the reverse curve (channelling)

Trouble-shooting

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