Comparison of the accuracy of phone applications with Snellen chart in determining visual acuity


  • Rehan Naqaish Al-Shifa Trust Eye Hospital, Rawalpindi
  • Amena Masrur Islamabad Medical and Dental College, Islamabad
  • Sidra Naseem Holy Family Hospital (HFH), Rawalpindi
  • Fatima Amjad Hera General Hospital, Makkah KSA
  • Anum Badar Combined Military Hospital (CMH), Rawalakot AJK
  • Mishal Batool House Officer Akbar Niazi Teaching Hospital (ANTH), Islamabad



Cell phone, Diagnostic techniques, Ophthalmological, Ophthalmology, Visual acuity, Snellen’s chart


Objective: To correlate the visual acuity assessment as tested by smartphone application with standard Snellen visual acuity.

Methodology: A total of 136 individuals were included in this analytical cross-sectional survey conducted at Shifa Foundation Community Health Center, Islamabad between January 2022 and January 2023. Individual’s age ? 18 years were included. Snellen’s visual acuity was assessed using a standard Snellen’s visual acuity chart by the optometrist, while the Paxos checkup by DigiSight technologies was used to assess visual acuity on smart phone using one appropriately color calibrated I-phone 7 device. Both assessments were done in physically separate areas to reduce observation bias. Visual acuity from each assessment was noted in the decimal format. Frequency distribution and Pearson’s correlation was calculated to ascertain the relationship between the two study variables.

Results: A total of 88 males and 48 females were included in the study (n=136). The mean age of patients was 29.72±9.0 years. The mean visual acuity of right and left eyes as assessed with Snellen’s chart were 0.88±0.2 and 0.86±0.22, respectively. The mean visual acuity for right and left eyes as assessed by Paxos checkup were 0.84±0.19 and 0.86±0.21, respectively. There was positive correlation was present in both eyes. The Pearson’s correlation for right eyes was r = 0.66 and significant at p = 0.001, while the correlation for left eyes was r = 0.71 and significant at p = 0.001.

Conclusions: There is a strong correlation between Snellen’s visual acuity assessment and assessment of visual acuity by the smartphone application. This makes the latter a viable strategy for screening at places where taking a Snellen’s chart might not be feasible.

Author Biographies

Rehan Naqaish, Al-Shifa Trust Eye Hospital, Rawalpindi

Postgraduate Trainee (Ophthalmology)

Amena Masrur, Islamabad Medical and Dental College, Islamabad

FCPS (Ophthalmology),

Associate Professor

Sidra Naseem, Holy Family Hospital (HFH), Rawalpindi

FCPS (Ophthalmology),

Senior Registrar

Fatima Amjad, Hera General Hospital, Makkah KSA

MBBS, MCPS (Ophthalmology),


Anum Badar, Combined Military Hospital (CMH), Rawalakot AJK

FCPS (Ophthalmology),

Assistant Professor






Original Articles