Purpose: Patients with eye diseases often have a better-seeing eye (BSE) and a worse-seeing eye (WSE). This review will carve out the current knowledge in which the relationship to BSEs and WSEs contributes to overall visual functioning and vision-related quality of life (VRQoL).
Methods: Searches were from database inception to the current date. Terms used for the search were "better eye", "worse eye", "utility", "life quality", "quality of life", "VFQ-25", and "visual acuity".
Results: There is a lack of a clear definition for BSE and WSE, and the used definitions are regularly dependent on the underlying eye disease. "BSE" and "WSE" can interact in terms of binocular inhibition or summation. Measured influences of the BSE and WSE on VRQoL are dependent on the underlying instrument used for the measurement. Several studies show impaired VRQoL if only one eye is affected from disease, with unimpaired vision of the BSE. VRQoL can improve significantly when treating the BSE and the WSE. In eye diseases with impairment of the central vision, there is a better correlation between the BSE and VRQoL. However, in eye diseases with peripheral vision impairment, eg, glaucoma, functional parameters of the WSE are better predictors for VRQoL.
Conclusion: The WSE appears to have a stronger influence on VRQoL than is generally assumed. This is especially the case if the underlying eye disease does not affect central vision but peripheral vision.
Keywords: better eye; life quality; utility; visual field; worse eye.