Optician Guide
Yamout Optical Center
Professional Dispensing & Optical Practice • Since 1978
Optician Guide
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Option B • Glass-Black
Tools
Lens Thickness Estimator
Quick professional estimator (single-vision). Use for counselling, frame selection, and index recommendation.
Input—
Effective Diameter (approx)—
Estimated Edge Thickness—
Counselling—
How the estimator works (simplified) +
Uses effective diameter + sag approximation. Final thickness depends on design, base curve, edge polish, and lab minimums.
Decentration per eye ≈ ((A + DBL) − PD) / 2
Effective diameter ≈ A + 2×decentration
Sag (approx) increases with power and diameter, and decreases with higher index.
Quick Rules
Smaller + rounder = thinner edge Core optics +
For minus lenses, thickness increases with distance from the optical center. Round/oval shapes keep the edge closer to the pupil and reduce corner thickness.
PD matching reduces thickness +
PD mismatch forces decentration. More decentration = larger effective diameter = thicker edges for minus lenses.
