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Portland presbyopia onset delay study

1 June 1995


The Portland Presbyopia Onset Delay Study (PPODS), was designed to ascertain if nearpoint visual abilities responsible for comfortable, clear nearpoint vision can be improved through vision therapy (VT) for 35+ year old pre-presbyopes. Subjects were divided into two groups: a control group and a VT group. Four months of home based VT were prescribed. Procedures used were accommodative push-ups, loose lens "tromboning", monocular lens rocks, binocular lens flips, distance rocks, eye stretches, and vergence stimulation. Improvement was seen in the vision therapy group as compared to the control group in increased vergence ranges, increased AC/A ratio, and increased accommodative facility. Accommodative amplitude was resistant to the therapeutic intervention, as was accommodative posture as measured by subjective cross grid techniques. Anecdotal comments from the VT subjects supported improved near point ability. Suggestions for further study are provided.


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