The Ocular Accommodation Research Lab

Ocular accommodation can be regarded as the autofocus system of the human eye. It allows objects placed at different distances from the eye to be seen clearly and this ability inevitably deteriorates with age. The Ocular Accommodation Research Lab at the University of Plymouth conducts investigations to measure the accommodative function using different techniques and instruments. 

The team also focuses on measuring morphological changes occurring in different structures of the eye when accommodating. In addition, the team carries out fundamental research on what sort of information is the human eye able to use in order to detect the sign of defocus and thus accommodate accurately to dynamic changes in target vergence. This information is commonly referred to as cues for accommodation. For instance, depth perception and chromatic aberration (Figure 1) are two strong cues that help the eye to accommodate.

Figure 1 

The image of a Maltese cross formed on the retina is different for myopic and hyperopic defocus if chromatic aberration or even-order aberrations (e.g. spherical aberration) are present (first and third row). When odd-order aberrations are present (e.g. coma), the images are the same (second row).

Figure 2

Example of accommodation to a sinusoidally moving stimulus. In order to characterise the accommodative response, gain (G) and phase (P) were calculated for each cycle of the sinusoidal.