Samsung isn't just using VR headsets as a means of boosting phone sales. The company's C-Lab has launched Relumino, a Gear VR app that uses augmented reality to compensate for vision problems. It can magnify the picture or adjust the contrast of what you're looking at if it's just a question of clarity, but it can also remap your field of view (to deal with blind spots or tunnel vision), outline objects and filter colors.
The app is free in the Oculus Store, and don't be dissuaded by the Korean-only product page -- it supports English.
Yes, it would be awkward and impractical to walk around wearing a VR headset (and your phone) at all times, so the current app is more for special situations. And Samsung knows it -- the Relumino team hopes to develop "glasses-like" hardware that achieves similar results without drawing attention to wearers or adding too much bulk. Even in its current state, though, this could be valuable for any visually impaired person who'd like to supplement their eyesight without springing for expensive specialized equipment.