Perceptions of Traditional Postpartum Practices With Hmong Women in the United States.

Contrast sensitivity (CS) measures the ability to discriminate objects that exhibit only subtle differences in shades and patterns, and may better reflect the vision needed to carry out everyday tasks. Similar to high-contrast visual acuity (VA), poor CS is linked to decreased functional independence and quality of life. However, in older adults, CS has been shown to be a stronger predictor of important outcomes, such as fall risk, mobility and balance, cognitive decline, driving performance, and self-reported visual quality of life, in comparison to VA. Moreover, since CS declines earlier and more steeply than VA after age 50, preserving and improving CS through cataract surgery, treatment for diseases like glaucoma, or optical aids is critical for maintaining function and well-being in later life. Despite substantial evidence supporting its clinical importance, there is no consensus on a clinically meaningful threshold for impaired CS in older adults. The most common method for defining CS impairment is to set a threshold two standard deviations below the study population mean. Across numerous studies this threshold is most commonly established as less than 1.55 logCS. However, these statistical cutoffs only indicate how far CS falls below a reference mean, not the threshold at which loss translates into meaningful functional impairment, such as struggling to navigate uneven sidewalks at dusk, reading medication labels in dim light, or even self-perceived vision disability. To fill this gap, we derived a functionally anchored contrast-sensitivity threshold tied to self-reported visual disability (SRVD) using the nationally representative cohort of Medicare beneficiaries aged ≥65 years from the National Health and Aging Trends Study (NHATS). Unlike prior work that relied solely on statistically derived cutoffs, we aimed to generate a CS threshold at which impairment is no longer a simple deviation from the population mean but instead translates into tangible impairment noted by the individual. Moving beyond purely statistical thresholds, this study provides a framework for understanding how deficits in CS contribute to late-life functional impairment such as loss of mobility, balance, and independence in daily activities.