What is This?
Back Vertex Distance (BVD) Calculator — a fast, free tool for precise contact lens power conversion. Enter sphere, cylinder and axis to compute diopter adjustments and convert spectacle prescriptions to contact lens equivalents. Ideal for optometrists, eye care professionals and contact lens wearers.
Features: accurate dioptre conversion, supports plus/minus cylinder, adjustable back vertex distance, mobile-friendly and easy to use for clinical and personal calculations.