June 2013
Volume 54, Issue 15
ARVO Annual Meeting Abstract  |   June 2013
Displacement of Optical Centers in Over-the-Counter Readers: A Potential Cause of Diplopia
Author Affiliations & Notes
  • Constance West
    Pediatric Ophthalmology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
    Department of Ophthalmology, University of Cincinnati, Cincinnati, OH
  • David Hunter
    Department of Ophthalmology, Boston Children's Hospital, Boston, MA
    Department of Ophthalmology, Harvard Medical School, Boston, MA
  • Footnotes
    Commercial Relationships Constance West, None; David Hunter, REBIScan, Inc (I), Boston Children's Hospital (P), Johns Hopkins University (P)
  • Footnotes
    Support None
Investigative Ophthalmology & Visual Science June 2013, Vol.54, 1301. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Constance West, David Hunter; Displacement of Optical Centers in Over-the-Counter Readers: A Potential Cause of Diplopia. Invest. Ophthalmol. Vis. Sci. 2013;54(15):1301.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Purpose: Induced prism in spectacle lenses, which may result from inadvertent displacement of optical centers, may worsen an existing heterophoria or even cause diplopia. Normal vertical fusional amplitudes are relatively small, making optical center displacement in the vertical meridian a particular concern. To evaluate the magnitude of this potential problem, we assessed the frequency and extent of clinically significant manufacturing variations in a random selection of over-the-counter reading glasses ("OTC readers.")

Methods: OTC readers of varying styles and powers were purchased from seven stores in three US states (West Coast, Midwest, and East Coast). The optical centers were marked using a focimeter. A prescription aligner was then used to measure interpupillary distance (PD) (distance between optical centers) and vertical displacement (relative distance of the optical centers from the lower frame edge). Monocular PD (distance of each optical center from its respective nasal frame edge) was also measured.

Results: A total of 160 OTC readers were evaluated. The optical centers were vertically displaced by ≥2 mm in 24% (41 pairs) and by ≥3 mm in 11% (18 pairs), with a maximum displacement of 7 mm in one pair. Average PD was 64 mm (range, 58 to 74.5 mm), with PD <60 mm in 2% (3 pairs) and >70 mm in 3% (5 pairs). Monocular PD was asymmetric by ≥ 5 mm in 4% (6 pairs). One pair was found to have a 0.75 diopter power difference between lenses.

Conclusions: Some OTC readers have misaligned optical centers and other manufacturing defects that are of a magnitude sufficient to exacerbate a heterophoria and cause asthenopia or diplopia. Defects occur commonly enough that clinicians should routinely measure the optical centers and power of OTC readers when evaluating a symptomatic patient.

Keywords: 722 strabismus • 653 presbyopia • 718 spectacle lens  

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.