Nuclear cataract and myopic shift in refraction

Am J Ophthalmol. 2007 Sep;144(3):457-9. doi: 10.1016/j.ajo.2007.05.003.


Purpose: Nuclear cataract is thought to cause a myopic shift in refraction in older persons. The authors tested this hypothesis by assessing the correlation of nuclear opacity with spherical equivalent refraction (SER) in an older population.

Design: Population-based cross-sectional study.

Methods: Three thousand six hundred and fifty-four participants aged 49 years or older were examined in the Blue Mountains Eye Study [BMES] (1992 to 1994). Eye examinations included subjective refraction and lens photographs. Nuclear opacity was assessed against four standard slit-lamp lens photographs using the Wisconsin Cataract Grading System. Nuclear cataract was defined as opacity level 4 or higher.

Results: Participants without nuclear cataract had an annual mean hyperopic shift of 0.05 diopters (P < .0001). In persons with nuclear cataract, this hyperopic shift disappeared. A myopic refractive shift occurred only in persons with nuclear opacity levels of 4 or higher.

Conclusion: This study documents the contribution of nuclear cataract to the mild myopic shift that neutralizes the age-related hyperopic shift occurring in older persons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / physiology
  • Cataract / complications*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Hyperopia / physiopathology
  • Lens Nucleus, Crystalline / pathology*
  • Male
  • Middle Aged
  • Myopia / etiology*
  • Myopia / physiopathology
  • New South Wales
  • Refraction, Ocular / physiology