Aim: To determine the effects of defocus on the retinal sensitivity within the central 2° and at 24° of the visual field and to compare the effect on the two areas.
Methods: Twelve normal subjects (aged 18–22 years) undertook three visual field tests on a Humphrey visual field analyser, one with a +3.00 DS lens, one with a +4.00 DS and one with a +5.00 DS. Mean threshold sensitivity was recorded in the central 2° and at 24°. Analysis of variance and paired t-tests were used for data analysis.
Results: Two participants were excluded. Analysis of the 10 remaining participants showed that the strength of lens used affected sensitivity (p < 0.0013), the difference Occurring when the +5.00 DS lens was used. Each lens had a similar effect on the central 2° and at 24° (p = 0.6706).
Conclusion: Threshold sensitivity was reduced with induced blur from plus lenses, without cycloplegia.