Lens Fitting

The I Kone™ Lens utilizes a larger overall diameter to distribute the weight of the lens more evenly across the cornea.

1. Begin with a base curve from the trial lens that is closest to the steepest corneal curve.
2. After evaluating the fluorescein pattern, make adjustments to the base curve, if necessary.
3. The base curve of the lens should not rest on the central cornea when determining the fit.
4. Continue to select base curves until a slight vault over the central cornea is accomplished.
5. The power is determined by a spherical refraction over the best fitting lens. The result should give a stable endpoint with acuity comparable to the best acuity expected from this patient. When ordering, adjust the lens power to reflect any change from the diagnostic base curve used in the over refraction. Also, remember to vertex over-refraction greater than 4.00 diopters.
6. The 9.6 overall diameter allows for a larger optical zone which provides better vision and reduces glare symptoms that are inherent with smaller lens designs. An 8.8 and 10.4 diameter is also available.
7. The peripheral curve on the back surface of the lens can be ordered steeper or flatter than the standard design of the diagnostic lens if necessary. Use slit lamp magnification, the periphery of the lens should appear to align with the underlining cornea and the edge should show adequate clearance.

• If the edge clearance is less than desired, the lens should be ordered with one step (.02) more lift.

• If the edge clearance appears to impinge on the cornea or there is no movement of the lens, the lens should be ordered with two steps (.04 mm) more lift.

• If the edge clearance is more than desired, the lens should be ordered with one step (.02 mm) less lift.

• If the edge rises significantly above the cornea and movement is excessive, the lens should be ordered with two steps (.04 mm) less lift.