Original Article
Exploration of Sensitivity Threshold of Human Eyes to the Change of Spectacle Lens Diopter and Clinical Study of Effect of Using Small Gradient Lenses
Tingting Yao, Jihong Wang
Published 2023-01-25
Cite as Chin J Optom Ophthalmol Vis Sci, 2023, 25(1): 56-61. DOI: 10.3760/cma.j.cn115909-20220415-00146
Abstract
Objective:To measure the sensitivity threshold of human eyes to the change of spectacle lens diopter, and to study the significance of small gradient lenses.
Methods:In this self-control study, a total of 100 patients were selected from the ophthalmic clinic of Affiliated Hospital of Jiangnan University from January to December 2021, and one eye was randomly selected as the test eye. All the test eyes were divided into three groups according to diopter: low hyperopia group (34 eyes), low myopia group (32 eyes) and moderate myopia group (34 eyes). Subjective optometry under non-cycloplegic state was performed in both eyes of the subjects using 0.05 D gradient lenses. Superimpose a piece of 0.05 D lens on the subjects' eyes when the red-green balance was achieved, and the sensitivity threshold was tested by observing the change of the clarity of the red-green visual target. If the red-green balance could not be achieved, the sensitivity threshold was less than 0.05 D. Self comparative study was used to compare the corrected visual acuity, contrast sensitivity, visual function test and the binocular balance of these one hundred subjects' eyes with the 0.25 D and 0.05 D gradient lenses respectively. Wilcoxon signed rank sum test was used to analyze data in each experiment.
Results:Ninty-five percent of the subjects' eyes had a sensitivity threshold of 0.05 D and less to the change of spectacle lens diopter , and there was no correlation between diopter and sensitivity threshold. The 0.05 D gradient prescription had better corrected visual acuity (Z=-7.40, P<0.001) and contrast sensitivity at four spatial frequencies (3, 6, 12, 18 c/d) than the 0.25 D gradient prescription (all P<0.001).There were no significant differences in accommodation flexibility, amplitude and accommodative vergence/accommodative between 0.05 D gradient prescription and 0.25 D gradient prescription (P>0.05). Binocular balance was easier to be achieved with the 0.05 D gradient prescription than the 0.25 D gradient prescription (r=0.44, P<0.001).
Conclusions:Without affecting visual function, small gradient lenses are more accurate and can provided a better visual experience and same visual clarity between both eyes.
Key words:
small gradient lenses; sensitivity threshold; visual function test; self comparative study
Contributor Information
Tingting Yao
Department of Ophthalmology, Affiliated Hospital of Jiangnan University, Wuxi 214122, China
Jihong Wang
Department of Ophthalmology, Affiliated Hospital of Jiangnan University, Wuxi 214122, China
