The effects of hydrogel contact lens wear on low contrast acuity

Abstract

There is evidence to suggest that hydrogel contact lenses may cause a reduction in the contrast sensitivity function of the eye. Lens surface deposits along with lens-induced changes to the corneal tissue have been implicated. The light scattering properties of lens materials may also differ. This double-masked study was designed to investigate whether low contrast acuity varies between different contact lenses. Low contrast acuity thresholds, intraocular light scatter and aberrations were assessed for six subjects while wearing each of six different hydrogel contact lenses and also no lens. Low contrast acuity thresholds were significantly higher for lens 4 but did not differ significantly between five of the lenses and the no lens condition. Neither higher order aberrations nor intraocular light scatter differed between the six lens types but we cannot rule out the possibility of small angle scatter associated with lens 4.

Keywords:

• low contrast acuity
• hydrogel contact lenses
• visual performance
• scattered light

Acknowledgements

We thank Professor John Barbur for his helpful comments on this paper. We thank the following contact lens manufacturers for providing the contact lenses used in this study: Ciba Vision, Johnson & Johnson Vision Care, Bausch & Lomb, Ultra Vision and Cantor & Nissel. None of the authors has any commercial interest in any of the contact lens manufacturers who provided lenses for this study. We thank Dr David Crabb for statistical support.