Study: Corrected presbyopes use larger text, longer viewing distances on smartphones

A cross-sectional study recently published in Ophthalmic and Physiological Optics found that corrected presbyopes used larger fonts, held smartphones farther away, and took longer to complete standardized reading tasks than nonpresbyopes.¹

For optometrists, the results support asking patients about device-specific working distances, font preferences, and reading tasks when prescribing presbyopic correction.

“Despite reading with a significantly larger font size, presbyopes required a longer viewing distance and more time to complete all reading tasks, indicating increased visual effort and adaptation during smartphone use,” the study authors, led by Carl Halladay Abraham, OD, of the School of Optometry and Vision Science at the University of Cape Coast in Cape Coast, Ghana, stated. “These findings highlight the additional visual demands experienced by corrected presbyopes during near digital tasks. Therefore, prescribers should consider the specific visual tasks an individual engages in when prescribing presbyopic correction rather than relying solely on the conventional 40 cm near working distance, as real-world smartphone usage may require different accommodative and ergonomic considerations.”

Study overview

Abraham and colleagues compared near-viewing behavior between corrected presbyopes and nonpresbyopes performing a series of standardized smartphone reading tasks under habitual viewing conditions.¹ The study was supported by facilities at the School of Optometry and Vision Science, University of Cape Coast, Cape Coast, Ghana.

Investigators recorded the time required to complete each reading task. Photographs captured from 2 m away were used to measure smartphone viewing distance and craniovertebral angle, an objective indicator of head and neck posture.

The primary outcomes included font size, task completion time, viewing distance, and craniovertebral angle. The abstract did not report the sample size, participant age distribution, type of presbyopic correction, or numerical between-group differences.

Time and distance

Corrected presbyopes selected significantly larger font sizes than nonpresbyopes for the reading tasks (P < .01). Despite using larger text, they viewed the smartphone from a significantly greater distance (P < .001) and took significantly longer to complete the tasks (P < .001).¹

These findings indicate that habitual correction did not eliminate measurable differences in smartphone reading behavior. The combination of increased font size, longer working distance, and slower task completion may represent adaptation to reduced accommodative ability or limitations in correction across real-world viewing demands.

The clinical magnitude of these differences remains unclear because absolute font sizes, viewing distances, and completion times were not provided in the available abstract. Consequently, statistical significance cannot be directly translated into a threshold for changing an addition power or selecting a specific lens design.

Craniovertebral angle did not differ significantly between groups (P > .05), suggesting that corrected presbyopes and nonpresbyopes adopted similar neck postures while completing the tasks. The study therefore did not identify a presbyopia-specific postural difference, even though visual behavior differed.

Clinical context and interpretation

Presbyopia results from age-related changes that reduce the eye’s ability to accommodate for near targets.^2,3 Smartphone reading introduces additional variables—including small text, limited screen dimensions, and user-selected working distances—that may not be replicated by a standard near-vision test.

Previous research has shown that smartphone viewing distance and character size vary across the lifespan.⁴ Digital device use also may be associated with ocular and visual symptoms collectively described as digital eye strain, although symptoms were not evaluated in the current study.⁵

For clinicians, the findings support a task-oriented presbyopia evaluation. In addition to measuring near acuity at a conventional distance, prescribers may consider observing the patient’s habitual smartphone distance and asking about text messaging, web browsing, reading duration, font enlargement, and transitions between phone, computer, and printed material.

The study does not establish that a particular correction strategy improves smartphone performance. It also cannot determine whether longer viewing distances and completion times reflect insufficient correction, learned behavioral adaptations, differences in age or digital familiarity, or other unmeasured factors.

Limitations and future research

The cross-sectional design precludes causal inference. Habitual corrections were evaluated rather than standardized interventions, and the available report did not describe correction modality, addition power, refractive status, smartphone characteristics, sample size, or participant demographics. Short standardized tasks also may not reproduce prolonged device use or associated symptoms.

Prospective studies should compare correction types and addition powers using quantified reading speed, visual comfort, preferred working distance, and sustained-use outcomes. Research incorporating different smartphone screen sizes and everyday digital tasks could help determine whether task-specific prescribing improves functional performance.

References

1. Abraham CH, Osman A, Sakyi-Badu G, et al. Smartphone near-viewing demands differ in corrected presbyopes: implication for presbyopic correction. Ophthalmic Physiol Opt. Published August 12, 2026. doi:10.1007/s44402-026-00168-3

2. Strenk SA, Strenk LM, Koretz JF. The mechanism of presbyopia. Prog Retin Eye Res. 2005;24:379-393. doi:10.1016/j.preteyeres.2004.11.001

3. Charman WN. The eye in focus: accommodation and presbyopia. Clin Exp Optom. 2008;91:207-225. doi:10.1111/j.1444-0938.2008.00256.x

4. Boccardo L, Gurioli M, Grasso PA. Viewing distance and character size in the use of smartphones across the lifespan. PLoS One. 2023;18:e0282947. doi:10.1371/journal.pone.0282947

5. Sheppard AL, Wolffsohn JS. Digital eye strain: prevalence, measurement and amelioration. BMJ Open Ophthalmol. 2018;3:e000146. doi:10.1136/bmjophth-2018-000146