Vision Categories – Epidemiology and Technology

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Height of Tumbling E for Visual Acuity Assessments at various distances

person holding eyeglasses

When developing mobile apps / charts for assessing visual acuities using Snellen's / LogMAR notation, there is a need to estimate the size of letters for a given working distance for assessing a specific cutoff. Under normal vision, for a visual acuity of 6/6, the whole letter subtends an angle

Visual Acuity Conversion Chart

In order to simplify my life when dealing with variations in Visual Acuity Charts when dealing with data from different surveys, I have created the following table for VA conversions What about PL+ / PL-, FCCF etc LogMAR for 1/60 vision is 1.78, rounded off to 1.8 as used in

ICD 11 Vision Categories

When analyzing data from blindness surveys, one needs to map out visual acuity against the Visual impairment categorized in ICD. There are some nuances, especially w.r.t Moderate visual impairment (MVI) based on the charts used as some VA charts yield 6/18 vision while others yield 6/19. ICD11 Categories Based on