How free care improved vision in the health insurance experiment.

We studied reasons for the improvement in the functional vision of enrollees receiving free care in the Rand Health Insurance Experiment. Among low income enrollees, 78 per cent on the free plan and 59 per cent on the cost-sharing plans had an eye examination; the proportions of those obtaining lenses were 30 per cent and 20 per cent, respectively. Visual acuity outcomes of low income vs non-poor enrollees were more adversely affected by enrollment in cost-sharing plans. Free care resulted in improved vision by increasing the frequency of eye examinations and lens purchases.