A versatile optoelectronic aid for low vision patients.

The purpose of this work is to describe a versatile optoelectronic aid for low vision rehabilitation based on reconfigurable hardware. This aid is easily adaptable to diverse pathologies (with different associated processing tasks) and to the progression of the visual impairment. This platform has a mobile configuration that uses a see-through head-mounted display (Nomad). We have implemented different types of vision enhancement on this versatile platform, and briefly summarize here their computational costs (in terms of hardware resource requirements). We have evaluated two representative capabilities of this aid (Augmented View and digital zoom) with measurements of visual acuity, contrast sensitivity and visual field. We have tested the Nomad head-mounted display and the Augmented View modality, in eight subjects with retinitis pigmentosa: the digital zoom was tested in six low vision subjects and nine normally-sighted subjects. We show that the Nomad display with Augmented View configuration does not impair the residual vision; and that there is an increase in visual acuity (VA) with the digital zoom configuration. The major advantage of this platform is that it can easily embed different image processing tasks and since it is based on a FPGA device, it can be specifically configured to tasks requiring real-time processing.