Web-Based Reading Assessment Tool Validated in Normal, Low Vision Testing

Woman having an eye test in a modern opticians
Woman having an eye test in a modern opticians, showing the latest up-to-date equipment
Researchers develop and validate a digital reading test.

Researchers say a web-based reading test for patients with normal and low vision is suitable for both clinical and research purposes, according to a report in Clinical Ophthalmology. The Democritus Digital Acuity Reading Test (DDART), is considered suitable for use in clinical and research settings, according to the study authors.  

The team developed wDDART in a prospective, comparative trial (Clinicaltrials.gov Identifier: NCT04618224). The program uses advanced text calibration, estimates the patient’s distance from the screen based on computer vision, and automatically calculates patients’ reading times, facilitating the overall examination procedure. 

The investigators compared reading parameters of wDDART (reading acuity [RA], maximum reading speed [MRS], critical print size [CPS], and reading accessibility index [ACC]) with those of a conventional Windows-based reading test (DDART) in patients with normal and low vision. They evaluated the test-retest reliability of wDDART for all reading parameters within a 15-day timeframe.

A total of 100 patients (50 men, 48.2±13.7 years of age) ) participated in the study and underwent evaluation with both DDART and wDDART. The low-vision group (n=30) included patients with various diagnoses, such as age-related macular degeneration (AMD), diabetic retinopathy, and glaucoma, among others. 

The researchers observed nonsignificant differences for all parameters of the 2 reading tests between the normal-vision group and low-vision group. Intraclass correlation coefficients (ICCs) between the 2 tests demonstrated good or excellent correlation for RA, MRS, ACC (from 0.866 up to 0.984) and moderate correlation for CPS (normal-vision group ICC, 0.686; low-vision group ICC, 0.660) but an excellent ICC for all participants (0.911). Test–retest reliability was excellent for RA (ICCs ranged from 0.905-0.976) and ACC (0.959-0.990) and moderate to good for MRS (0.882-0.946) and CPS (0.715-0.931).

“To our knowledge, wDDART is the first validated ophthalmological reading assessment tool that is available as a web application,” according to investigators. “Study outcomes suggest its sufficiency for clinical and research settings.”

Currently, wDDART is validated for Greek-speaking populations. However, the investigators note that its underlying technology supports all languages and the system can be adapted and potentially used to support for screening initiatives and remote care in other populations.


Labiris G, Panagiotopoulou EK, Duzha E, et al. Development and validation of a web-based reading test for normal and low vision patients. Clin Ophthalmol. 2021;15:3915-3929. doi:10.2147/OPTH.S314943