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Foveal flicker contrast sensitivity was measured for healthy adults at temporal frequencies from 2.5 to 50 Hz. The first experiment compared two-interval forced-choice (2IFC) and yes-no detection (Y-N) testing procedures for younger (19-33-year-old) and older (67-73-year-old) observers. The 2IFC technique resulted in higher absolute estimates of sensitivity. However, within a method, relative differences were similar. Therefore the two methods gave similar estimates of temporal contrast-sensitivity change with age. Experiment 2 compared 89 observers from 18 through 77 years of age to explore the effect of the time course of aging on flicker sensitivity. The 2IFC procedure was used, and retinal illuminance changes with age were controlled. Significant overall losses in contrast sensitivity were found for the 45-54, 55-64, and 65-77-year-old age groups. Overall sensitivities for the 35-44-year-old group were comparable with or (not significantly) higher than those for the 18-24- and 25-34-year-old groups. The results suggested that (1) foveal temporal contrast sensitivity does not decline until after 44 years, (2) losses after 44 years are in amplitude but not in temporal resolution of the visual response, and (3) the mean rate of loss is approximately 0.78 decilog per decade after 44 years. These results are consistent with the existence of three phases of development of temporal contrast sensitivity over the life span. The results also emphasize the importance of including healthy-eyed age-matched controls in studies of flicker sensitivity in visual dysfunctions that affect mainly older adults.

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Purpose Degenerative myopia is a significant cause of vision loss; yet there is no accepted way of controlling its causative phenotypeFprogressive high axial myopia. Scleral reinforcement, introduced over 50 years ago, was discredited as a useful technique. This 5-year 'proof of concept' study examines buckling of the posterior pole for myopia control and follows the course of untreated fellow eyes. Method A total of 59 adult eyes, with myopic refractive corrections ranging from À9 to À22 D and axial lengths from 27.8 to 34.6 mm, were studied. A 1-cm-wide flexible buckle of donor sclera was positioned over the posterior pole and secured, under positive tension, to the anterior globe. The eyes were monitored for 5 years, as were unsupported fellow eyes. The axial lengths, visual acuities, and optical coherence tomography macular scans were collected and all complications were noted. Results Over 5 years, axial length control was achieved by scleral buckling, whereas axial extension progressed in the untreated group. No serious complication occurred and no eye lost visual acuity from the procedure. Temporary intra-ocular pressure elevation, small choroidal effusions, and variable periods of abduction limitation occurred after surgery. In one case of tractional myopic macular schisis, a full correction was achieved by buckling and visual acuity improved.

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