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Purpose: To report the proportion of older people in England who wear distance spectacles full time, part time and rarely, and to investigate factors that influence how much the distance vision (DV) correction is worn., Methods: A two-part questionnaire investigating the spectacle-wearing habits of older people was developed and completed by 322 participants (age 72 years ±7.7, range 60-94). A subcohort of 209 DV correction wearers with a mean spherical equivalent (MSE) of <±4.00DS was selected for a logistic regression to investigate which factors influence how much the DV correction is used., Results: In total, 43% of emmetropic, and 55% of pseudophakic, DV spectacle wearers wear their correction full time. Lens type, MSE and the age that participants first wore a DV correction significantly predicted DV correction wearing habit (adjusted R 2  = 0.36), with lens type being the strongest predicting factor and progressive users wearing their spectacles 37% more than those using single vision lenses., Conclusions: Many patients appear to consider convenience more important than being spectacle independent at distance, with lens type the most significant influencing factor of how much those with low/moderate refractive error wear their distance correction. Many emmetropes and pseudophakes choose to wear their progressive or bifocal spectacles full time, and the emmetropia provided by cataract surgery does not provide independence from full-time spectacle wear for many patients. The optometrist has a key role in discussing both choice of spectacle lens correction and the refractive outcome options of cataract surgery with patients., (© 2023 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

In addition to his work on physical optics, Thomas Young (1773-1829) made several contributions to geometrical optics, most of which received little recognition in his time or since. We describe and assess some of these contributions: Young's construction (the basis for much of his geometric work), paraxial refraction equations, oblique astigmatism and field curvature, and gradient-index optics., (© 2011 The Authors. Clinical and Experimental Optometry © 2011 Optometrists Association Australia.)

Two infant vision screening programmes on total populations in the Cambridge Health District have been designed to identify manifest strabismus and strabismogenic and amblyogenic refractive errors at 7-9 months of age. The first, completed, programme used the isotropic photorefractor with cycloplegia together with a standard orthoptic examination. The second, current, programme uses the VRP-1 isotropic videorefractor to identify infants with accommodative lags which are followed up by refraction under cycloplegia. Both programmes show good agreement between infants identified at screening and retinoscopic refractions at follow-up, showing that photo- and videorefraction (with or without cycloplegia) can be effective methods for screening for ametropia in infants and young children. In each programme 5-6% of infants showed abnormal levels of hyperopia (> or = 3.5 D in any meridian), less than 1% showed anisometropia > or = 1.5 D; very few infants (0.25%) showed -3D myopia or greater. Less than 1% showed manifest strabismus. Hyperopic and anisometropic children entered a randomised controlled trial of partial refractive correction. All children identified at screening, alongside appropriate control groups, are extensively followed up to age 4 years. The first programme has found that children who were hyperopic in infancy were 13 times more likely to become strabismic, and 6 times more likely to show measurable acuity deficits by 4 years, compared with controls. Wearing a partial spectacle correction reduced these risk ratios to 4:1 and 2.5:1 respectively. The impaired acuity can be attributed, in part, to meridional amblyopia resulting from persisting astigmatism. Both hyperopic and myopic infants showed refractive changes in the direction of emmetropia between 9 months and 4 years. Wearing a partial spectacle correction did not affect this process of emmetropisation, but does provide the possibility of reducing the incidence of common pre-school vision problems.

The data for this paper were collected during a two-year study of the elderly in the market town of Melton Mowbray. The data show that typically, persons aged 75 years and older have poor uncorrected vision (6/36 Snellen acuity), but good corrected acuity, 73.8 per cent gaining 6/12 binocular Snellen acuity or better. Over 88 per cent were able to read N8 typesize or better, under test conditions. Those with low uncorrected vision were the most likely to possess spectacles.