Optonet Project

Standardization of Visual Acuity

Quality logMAR VA Charts for Healthcare

Equip your clinic with a digital logMAR VA system

Affordable ​and easy to implement

logMAR VA Charts

Superior to traditional ETDRS charts


Optonet logMAR visual acuity (VA) charts allow several repeated measures to be taken quickly, to improve precision. Letters can be changed randomly infinite times, thus avoiding memorization.

Optonet proposes to always take two VA values and keep the mean. Preliminary real-world data obtained with this method shows a remarkable Test Retest Variability (TRV) of 3.5 ETDRS letters.

Random logMAR Visual Acuity
Visual Acuity Monitoring


Quick repeated measures also enable to identify the patient’s individual criterion for change to monitor VA changes over time.

Optonet does this automatically, calculating mean and standard deviation.


The Vision Unit offers the option of half steps of letter size changes (0.05 log instead of 1.0 log).

This option significantly increases the accuracy of the VA measurements.

Half Steps Visual Acuity


It is a progressive hybrid web-based app that can be accessed on any computer or tablet and displayed on any conventional computer screen.

Scoring System

It offers an easy automated system for recording patient answers, which is faster and minimizes calculation errors.

VA values can be automatically stored in the patient’s file, avoiding transcription errors.


Measurement Time

Modified procedures can easily be adopted to reduce measurement time.

Both, the automated scoring and storing system also save valuable time during consultations.


Computer screens provide better background luminance and durability than printed charts on illuminated cabinets.

logMAR Visual Acuity
4K Visual Acuity


The Optonet Unit is compatible with 4K monitors (28″), which can display the same number of 5-letter rows presented in standard ETDRS VA charts, and with image quality akin to backlit ETDRS printouts (the “Gold Standard” for VA measurement until now).

Optonet system in combination with a 4K monitor is probably the most accurate (digital) system available for VA measurement in hospitals and research.

To display the Optonet system, the 28” 4K screen requires a computer (a mini PC* is recommended for its reduced size and price). Android multimedia devices are not compatible.

*Android multimedia devices are not compatible with 4K screens for Optonet VA charts.

Cost Efficiency

The OVU can be displayed on pre-existing equipment; or the clinic can purchase equipment to fit their budget, ranging from an Android TV device paired with a conventional monitor (low-cost option), to a mini-PC computer attached to a 4K screen (highest resolution option).


Android TV