Contact Lenses: Using 2 Tests of Dominance to Optimize Presbyopic Fitting

Overview

Assessing ocular dominance through both sighting and sensory tests enhances the fitting of presbyopic contact lenses. Employing these tests aids in tailoring monovision and multifocal lens prescriptions, improving patient adaptation and visual comfort.

Background

Ocular dominance plays a critical role in contact lens fitting, especially for presbyopes. Sighting dominance identifies the preferred eye for aiming at a target, while sensory dominance measures the eye's strength in visual processing under binocular conditions. Using both tests provides a comprehensive understanding of dominance, which is essential for optimizing monovision and multifocal lens outcomes. This approach helps address alternating dominance and varying visual demands at different distances.

Data Highlights

The article describes two primary ocular dominance tests: the sighting test (hole-in-card method) and the sensory test (resistance to blur using +1.00 D lenses). It emphasizes that combining these tests confirms dominance, especially when eyes differ in correctability, and guides lens power adjustments to minimize disparity and enhance binocular visual comfort.

Key Findings

• Sighting dominance alone is insufficient; combining it with sensory dominance testing provides a more reliable assessment.
• The sensory test involves introducing +1.00 D blur over each eye to determine dominance strength based on resistance to blur.
• Monovision fitting benefits from minimizing refractive disparity between eyes, prescribing the most plus to the best distance eye and least plus to the best near eye.
• Some patients prefer the dominant eye for near vision, influencing fitting strategies for near-demanding activities.
• Multifocal lenses generally require equal distance and near correction, but a hybrid approach with full correction in the dominant eye and slight acuity reduction in the non-dominant eye can improve outcomes.
• Modified monovision approaches, such as adding +0.50 D to the non-dominant eye, can enhance intermediate vision comfort with multifocal rigid gas permeable lenses.

Clinical Implications

Clinicians should employ both sighting and sensory dominance tests to accurately determine ocular dominance before fitting presbyopic contact lenses. Tailoring lens power based on dominance can improve patient adaptation, visual comfort, and satisfaction, particularly when considering monovision or multifocal designs. Evaluating binocular visual comfort under normal lighting conditions is essential to optimize fitting outcomes.

Conclusion

Identifying and understanding ocular dominance through dual testing remains a valuable strategy in contact lens fitting for presbyopes. Integrating these assessments supports customized prescriptions that enhance visual performance and patient satisfaction.

References

1. Robboy MW, Cox IG, Erickson P. 1990 -- Effects of sighting and sensory dominance on monovision high and low contrast visual acuity