Horwood,A, Riddell P. Vision Research 2008 , 48(15), 1613-24
- Binocular disparity is the main drive to both accommodation AND convergence.
- In comparison, blur and proximity/looming are weak cues in adults
A remote haploscopic video refractor was used to assess vergence and accommodation responses in a group of 32 emmetropic, orthophoric, symptom free, young adults naïve to vision experiments in a minimally instructed setting. Picture targets were presented at four positions between 2m and 33cm. Blur, disparity and looming cues were presented in combination or separately to asses their contributions to the total near response in a within-subjects design.
Response gain for both vergence and accommodation reduced markedly whenever disparity was excluded, with much smaller effects when blur and proximity were excluded. Despite the clinical homogeneity of the participant group there were also some individual differences.