Resources
Mastering Decentration: Your Practice Exercise for Ophthalmic Frames
Understanding Decentration Decentration is the displacement of a lens’s optical center from the patient’s visual axis. There are two key concepts, Vertical and Horizontal Decentration. Vertical decentration, commonly called Seg Drop, is defined as the offset of a bifocal lens’s reading zone below the center of the frame. Lenses may require vertical decentration (upward or … <a href="https://opticaltraining.com/blog/mastering-decentration-your-practice-exercise-for-ophthalmic-frames/">Continued</a>
Brianna Cuenca
Base Curve Basics
All About Base Curve Base curve refers to the front curvature of a lens and is measured in diopters. You can determine total dioptric power of a lens by adding the base curve (front surface) and the ocular curve (back surface). The base curve chart illustrated below contains very general information regarding base curve selection. … <a href="https://opticaltraining.com/blog/base-curve-basics/">Continued</a>
Brianna Cuenca
Mastering Minimum Blank Size: Your Practice Exercise for Ophthalmic Frames
Minimum Blank Size The minimum blank size is the minimum size of a lens blank that can be used to fit the frame chosen for an order. In order to calculate the minimum blank size, you must know how to calculate decentration. The formula used for minimum blank size will depend on the type of … <a href="https://opticaltraining.com/blog/mastering-minimum-blank-size-your-practice-exercise-for-ophthalmic-frames/">Continued</a>
Brianna Cuenca
Lenses as Prisms
Basic Optical Principles for using Lenses as Prisms When two prisms are placed base to base, they can be said to form a plus lens. Plus lenses cause parallel rays of light to converge or come together. The images formed by a plus lens are called real images because the rays of light actually come … <a href="https://opticaltraining.com/blog/lenses-as-prisms/">Continued</a>
Brianna Cuenca
Multifocal Lens Designs and Image Jump
Image Jump Since the reading segment may be thought of as a small plus lens which has been added to a larger lens, we may also think of it as a set of prisms placed base-to-base. If we consider only those prisms which are vertically oriented, it will look something like the illustration below. This … <a href="https://opticaltraining.com/blog/multifocal-lens-designs-and-image-jump/">Continued</a>
Brianna Cuenca
