Amaechi, O. U. and Osunwoke, C. M.
Abstract
The effects of blue and green filters on the binocular amplitude of accommodation were compared. Fifty healthy emmetropic volunteers aged 20 to 30 (mean age 24.18±1.52) years were the study subjects. The binocular amplitude of accommodation was first measured through the ‘no lens’ situation using the push-up-to blur method to obtain the baseline value. The measurements were repeated through a pair of blue filters and green filters inserted separately into the trial frame. The analysis of variance at 0.05 level of significance was used to analyze the data. The Dunkad comparison test at 0.05 level of significance was further used to compare the effects of the variables. Results showed that the blue and green filters significantly decreased binocular amplitude (P = 1.84 and 2.74 respectively). There was no significant difference between the comparative effect of blue and green filters on the binocular amplitude of accommodation. The importance of filters in achieving a comfortable vision for the patient has further been highlighted, however, the choice of which filter to use between the blue and green filters would depend on patient preference.
Keywords: Amplitude of accommodation, Blue filters, Green filters, Eye strain, visual stress.