B. Surya, M. Optom
Assistant Professor, Vinayaka Mission Research Foundation (Deemed to be University),
In the digital world, prolonged screen use is unavoidable for students and professionals. Among contact lens wearers, common complaints include dryness, headaches, blurred vision, and eye fatigue. These symptoms are often attributed primarily to dry eye or excessive device use. However, an important yet often overlooked contributor is binocular vision dysfunction, the ability of both eyes to work together efficiently. Recognising this connection is crucial for accurate diagnosis and effective management of digital eye strain.(1)
Digital Eye Strain Is More Than Dry Eye
Digital Eye Strain (DES) is not limited to ocular surface issues. It is a multifactorial condition involving tear film instability and increased visual demand. Screen use significantly reduces blink rate and completeness, leading to faster tear evaporation and dryness. Simultaneously, sustained near work places continuous stress on accommodative (focusing) and vergence (eye alignment) systems. Over time, this prolonged effort reduces visual efficiency, causing symptoms such as fatigue, difficulty focusing, and intermittent blur, especially in individuals with undiagnosed binocular vision anomalies. (2)
How Contact Lenses Influence Binocular Vision
Soft contact lenses, while convenient, can subtly affect binocular coordination during near tasks. Reduced oxygen transmission may lead to mild corneal oedema, slightly altering corneal curvature and near-refractive accuracy. In addition, lens movement and decentration during blinking can introduce small, fluctuating prismatic effects, requiring constant vergence adjustments. Lens dehydration further reduces wettability, leading to unstable vision and reduced clarity over time.
Individuals with stable visual systems often tolerate these micro-level stresses but can become significant in those with conditions such as convergence insufficiency or accommodative infacility. In such cases, contact lens wear may increase visual demand and worsen symptoms during prolonged digital tasks. (1)
Contact lenses can subtly alter visual function, especially during prolonged screen use.
| Factor | Impact on Vision |
|---|---|
| Reduced oxygen transmission | Mild corneal oedema altering refractive state |
| Lens movement | Induced variable prism affecting vergence |
| Lens dehydration | Reduced wettability and visual clarity |
Figure 1: This table shows the factors and their impact on vision.
These changes become clinically significant in individuals with:
-
Convergence insufficiency
-
Accommodative infacility
The Vicious Cycle
A self-perpetuating cycle frequently develops reduced blinking during screen use destabilises the tear film, contact lenses increase tear evaporation, and binocular dysfunction raises visual demand. Together, these factors intensify eye strain and discomfort. Notably, symptoms may persist even after removing contact lenses, indicating involvement beyond surface dryness.(3)
Management Strategies
Effective management requires a comprehensive approach. Clinicians should use validated tools such as the CVS-Q. (3) and perform binocular vision assessments, including near point of convergence and accommodative facility testing. (2) Vision therapy or near additional lenses may be beneficial when indicated.(2)
For contact lens users, simple strategies can reduce symptoms. Practicing conscious blinking, following the 20-20-20 rule. (1) and maintaining a viewing distance of 18–24 inches are helpful. Daily disposable silicone hydrogel lenses may improve comfort through better hydration and oxygen transmission. (3) Persistent symptoms should prompt binocular vision evaluation rather than repeated lens changes.(2)
Figure 1: This image shows the person experiencing digital eye strain while using a laptop
Image Courtesy: https://www.pexels.com/search/eye%20strain/
Conclusion
Contact lenses do not directly cause binocular vision dysfunction but can reveal or worsen underlying issues during prolonged screen use. Addressing both ocular surface health and binocular vision function is essential for effectively managing digital eye strain and ensuring long-term visual comfort.(2)
References
- Pucker AD, Gawne TJ. Digital eye strain: Updated perspectives. Clinical Optometry. 2024;16:135–147.
- Barata MJ, Aguiar P, Grzybowski A, Moreira-Rosário A, Lança C. A Review of Digital Eye Strain: Binocular Vision Anomalies, Ocular Surface Changes, and the Need for Objective Assessment. Journal of Eye Movement Research. 2025;18(5):39.
- Mastrota KM. How to recognize and manage digital eye strain. Optometry Times. 2024.
About the Author
B. Surya
Assistant Professor
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