OTC READERS
Evaluation, Testing and Results of Over the Counter Readers vs. ANSI Z80.1 Standards
10th October 2020 Kevin Walker ABOC
OVERVIEW For years, Optical professionals have questioned the quality, integrity and prescription validity of Over The Counter (OTC) Readers. The Z80.31 for OTC readers focuses mainly on the country of manufacture, materials, State Limitations on Power and limited optical standards. In this study, a variety of OTC Readers were tested to determine if they meet minimum ANSI Z80.1 (ANSI Z80.1-2015 Ophthalmics - Prescription Ophthalmic Lenses*1) Standards. The ANSI Z80.1 metric was used as the determining factor if the OTC passed or failed. As Opticians, we utilize this base standard to approve eyewear to be dispensed to a patient. Headaches, eye strain, and even
nausea can result from wearing reading glasses that are too far off from your actual prescription or that have optical centers too far away from the center of your pupils.*2
ANSI STANDARDS- Z80.31 The ANSI Standard for OTC Readers (ANSI Z80.31-2017 Ophthalmics -Ophthalmic Optics - Specifications For Ready-To-Wear Near-Vision Spectacles) is the current Standard in place for OTC Readers. The current 2017 Standard now addresses the refractive and prismatic power properties and their need to comply with requirements in ANSI Z80.1, as applicable. The standard also gives additional guidance on State power regulation, materials and country of Origin.
CONTROL GROUP OTC Readers were acquired from: Drug Stores, Supermarkets, Chain Retailers, Wholesalers, Optometry and Ophthalmology offices. Each OTC of varying powers was randomly subjected to testing. There were two control groups in the study. ● ●
PDxx- Stated PD, priced from $1.00 to $50.00
NPDXX- N o PD stated, priced from $0.99 to $45.00
TESTING OVERVIEW OTC Readers were tested by a Licensed Optician, Kevin Walker, ABOC. There were 100 pairs of OTC Readers evaluated, 50 of each Control Group. In order to verify power and determine minimum ANSI Z80.1 tolerance, a manual Lensometer was utilized. The Lensometer was calibrated and focused before usage. Each Pair was dotted and measured to determine PD. Errors were marked with a White Marking Pen to enhance and record with a visual record.
CRITERIA There were four criteria to determine a pass/fail of the OTC in question. The ANSI Z80.1 Standards were utilized to determine if tested media falls into the tolerances allowed. If the OTC Reader could not meet the minimum ANSI Z80.1 standard, it was deemed a failure.
PASS/FAIL CONDITIONS 1.
INCORRECT POWER (IPW)- If the Stated Power did not match the measured power, it failed. Furthermore, if the powers of the Right (OD) Lens did not match the Left (OS) Lens, it was rejected as well.
2. UNWANTED PRISM (UNP)- Horizontal prism was determined when the PD was outside of the ANSI Z80.1 Standards. Control group PDxx had a PD stamped on the frame. Determination- Prentice's Rule (△= D*d/10) is used to calculate the unwanted prism. Prentice's Rule calculates the unwanted prism that is created when the measured Optical Center of the lens deviates from the stated or expected OC. Any variance would result in an induced horizontal prism. 3. UNWANTED CORRECTION (UNC)- Unwanted cylinder and vertical prism correction were detected and noted throughout the evaluation. This was determined by the manual Lensometer and detection of the unwanted cylinder and vertical prism was verified by looking through the eyepiece and alignment of the mires. As a result, OTC was rejected. 4. LOCALIZED ERRORS (LOE)- Are unwanted errors or aberrations caused by a wave, warpage or internal defects when blur is found by a lensometer. Areas outside of 30mm (ANSI Z80.1-2015 standards) were exempt.
CONCLUSION OTC Readers that were tested resulted in a 34% rejection based on the ANSI Z80.1 criteria. An additional 17 pairs were at the minimum standard. With the mass production and lack of inspection of individual OTC Readers, it is apparent that Optical quality is greatly compromised. Eyecare Professionals, who follow ANSI Z80.1 for Dress Eyewear, are bound to adhere to standards for all eyewear is dispensed. When offering or evaluating OTC Readers, my recommendation would be the inspection of each pair of OTC, or offer in-house manufacturing, thereby controlling the factors to ensure that minimum ANSI Z80.1 standards are met.
CONTROL DATA RESULTS
PDXX FAILS (8 Samples)
NPDXX FAILS (8 Samples)
References *1 American National Standards, (Editorially Revised January 2016) ANSI Z80.1-2015. Retrieved from https://webstore.ansi.org/standards/vc%20(asc%20z80)/ansiz802015 *2 Vision Council PDF, 2020