Understanding Tool Logic & Output

• "Calculated CL Targets" Section:

  This shows the theoretical CL powers after VC and rounding, *before* checking specific lens availability.

  • Raw VC Power: Unrounded result from the VC formula.
  • Target Power: Raw power rounded using the cyl rule and a *generic* sphere rounding (0.25D steps, ±20D range) for initial display. This target sphere is then re-rounded against *specific* lens steps during matching.

  Use this as a reference to understand the calculation steps.

• "Final Rx" in Lens Results:

  This is the calculated *starting* CL prescription for the specific lens shown, after applying lens-specific rounding, potential fitting guide adjustments (e.g., Clariti MF), and optional SE compensation.

• Correction Type / Dominant Eye Options:

  These only activate if Near Add > 0.00D, as they relate to presbyopia correction (Monovision or Multifocal). Dominance is needed for Monovision and some MF designs (e.g., CV Biofinity D/N).

• Correction Type - Monovision Explained:
  • Goal: One eye (dominant) corrected for distance, the other (non-dominant) for near.
  • Calculation:
    1. Full Near Add is added to the *spectacle* sphere of the non-dominant eye.
    2. Vertex correction is performed separately on the dominant eye's distance Rx and the non-dominant eye's adjusted (distance + add) Rx.
    3. Looks for standard *Spherical* or *Toric* lenses matching these two different targets.
  • Result Display: Standard Sph/Toric lenses shown. Non-dominant Rx is higher (more plus/less minus). Notes indicate "[Monovision Near/Distance Eye]".
• Correction Type - Multifocal Explained:
  • Goal: Simultaneous distance and near vision in both eyes via lenses with different power zones.
  • Calculation: Uses *generalized* principles based on spectacle Add to select an initial CL Add power (Low/Med/High or +1.00, etc.) and sometimes a design (e.g., D/N) based on database rules (see lens data). Some guides (like Clariti MF) also require initial sphere adjustments based on Add/Dominance/Rx. The tool attempts to apply these adjustments to the *target CL sphere* before displaying the starting Rx.
  • Result Display: Shows Multifocal or Multifocal Toric lenses with a recommended Add/Design and potentially an adjusted sphere.
  • Crucial Note: Multifocal fitting varies significantly by brand. Always consult the specific manufacturer's fitting guide. This tool offers only a *potential* starting point, including attempted fitting guide adjustments.

Interpreting Lens Matches

• When is Toric Suggested?

  If the *Final Rounded Target CL Cylinder* is -0.75D or stronger (more minus).

• Compromise Fit - SE Compensation (Toric - Optional):

  Scenario: Target Cyl > Lens Max Available Cyl (and difference ≤ 1.00D and option enabled).

  Tool Action:

  1. Selects Max Lens Cyl.
  2. Calculates sphere adjustment: Adj = (Target Cyl - Lens Cyl) / 2.
  3. Adds adjustment to *initial target sphere* and rounds the result using the specific lens's available steps for that cylinder.

  Result: Notes highlight this ("Sphere adjusted... SE Compensation"). Yellow border.

• Compromise Fit - SE Substitution (Spherical MF for MF Toric Need):

  Scenario: MF Toric needed, but tool shows a Spherical MF lens.

  Tool Action: Sphere shown is the **SE** of the *final rounded target CL sphere & cylinder*. Add is selected per guide.

  Result: Notes highlight this ("Using SE Sphere... Astigmatism not corrected"). Significant compromise. Yellow border.

• Ideal Fit - True Multifocal Toric:

  Scenario: MF Toric needed, matching MF Toric lens found.

  Tool Action: Uses *Final Rounded Target CL Sphere, Cylinder, Axis* directly (sphere rounded to available steps for chosen cyl). Selects Add/Design per guide.

  Result: Corrects astigmatism & presbyopia. Standard (Green) or Compromise (Yellow) border depending if any SE compensation was needed (e.g., if target MFT cyl > lens max MFT cyl).

• Fit Adjustment - Fitting Guide Sphere Modification (e.g., Clariti MF):

  Scenario: Specific multifocal lens (like Clariti MF) fitting guide dictates an initial sphere adjustment based on Add, Dominance, and Rx type.

  Tool Action: Applies the guide's recommended sphere adjustment (e.g., +0.25D or +0.50D) to the *target CL sphere before final rounding*. The Add (e.g., Low/High) is selected based on the Spectacle Add.

  Result: Notes indicate this ("Guide Adjustment: Sphere adjusted..."). Standard (Green) or Compromise (Yellow) border depending on whether this adjustment *creates* a compromise state.

• Compromise Fit - Distance-Only Toric (for MF Toric Need):

  Scenario: MF Toric needed, but only a standard Toric lens match found.

  Tool Action: Shows standard Toric fit correcting distance sphere/cyl/axis.

  Result: Notes indicate Add is not addressed ("Covers Distance Rx only..."). Yellow border.

• Result Grouping & Sorting:

  Default sort ranks results within brands:

  1. Match Priority (Pair): Best Fit (1) > Compromise (2). Considers the *better* eye fit (revised logic).
  2. Lens Type Preference (Presbyopia): In Multifocal mode, prefers lens type matching need (MF Toric > MF > Toric > Sphere), if pair priorities are equal.
  3. Modality: Daily > Bi-Weekly/Fortnightly > Monthly.
  4. Material: Silicone Hydrogel > Hydrogel.
  5. Alphabetical: Family Name, then Full Lens Name.

  Sorting "Across Brands" removes grouping and applies the chosen sort key globally.

• XR (Extended Range) Lenses:

  Only suggested if target power is *outside* the standard lens range (e.g., Biofinity XR vs Biofinity). Often have 0.50D steps and potentially different sphere ranges depending on cylinder (e.g., Biofinity XR Toric). Verify availability and steps with official guide.

• Input Formatting:

  Sphere/Cyl/Add dropdowns ensure valid powers. Axis/VD inputs snap to integer ranges on change/blur.

Applying This in Practice

• Tool Limitations: This tool provides a *calculated starting point* only. It CANNOT replace your clinical judgment or a proper fitting process.
• Essential Clinical Steps (Always Perform):
  • Comprehensive Eye Exam (Refraction, Health Check)
  • Keratometry (Corneal Curvature)
  • Biomicroscopy (Slit Lamp Exam)
  • Tear Film Evaluation
  • **Trial Lens Evaluation:** Assess fit (movement, centration, coverage), vision (over-refraction), and comfort *on the eye*. The first lens is just a starting point!
• Verify Parameters: Lens availability (powers, BC, Dia) changes. Always consult current manufacturer fitting guides or product information.
• Use Fitting Guides: Essential for Toric & Multifocal fitting details, optimization, and troubleshooting.

Illustrative Multifocal Refinement Principles

(General concepts - Consult specific guides for accuracy!)

• General: Assess binocularly after settling (~10-15 mins).
  • Distance Blur: Try +0.25D sphere binocularly (or dominant eye).
  • Near Blur: Try +0.25D sphere non-dominant eye.
  • Modify sphere *before* changing Add/Design. Avoid minus sphere initially.
• CV MyDay: Dom eye fixed Low Add. Refine non-dom sphere/add PRN. Then adjust dom sphere.
• CV Biofinity D/N: Follow D/N rule. Refine sphere first before changing Add/design. (Applies to MF & MF Toric).
• Alcon Center-Near (DT1 MF, Total30 MF, Air Optix MF): Refine sphere +/-0.25D (max plus) before changing Add level.
• J&J Center-Near/Pupil Optimized: Refine sphere first before considering Add change.
• B+L Progressive: Refine sphere first, consider Add change later.
• CV Clariti MF (and Umere MF): Refine sphere first (±0.25D steps). For distance issues, adjust **Dominant** eye. For near issues, adjust **Non-Dominant** eye. **Do not change Add power** during initial refinement.