The increased pressures encountered while diving may cause a hollow orbital implant to collapse, resulting in cosmetic problems and a need for further surgery to replace the damaged implant.
Many ocular plastic surgeons are now using implants made of hydroxyapatite, a porous material which is not a contraindication for diving.
In general, it's best to wait until the underlying acute condition has resolved and there are no distracting or disabling ocular symptoms to contend with before returning to diving.
Deciding on your own visual acuity is primarily a judgment call, with few relevant scientific studies available to help resolve the issue. The approach taken in the article was to use statutory visual standards established for another hazardous activity - driving a car, for example - whose visual requirements are more demanding than diving. The recommendation made was that if you see well enough to qualify for a driver's license and operate a motor vehicle safely, then you should be able to see well enough to dive safely.
If a prospective diver has visual acuity which is poor enough to preclude him or her from being allowed to drive, then the fitness to dive decision needs to be individualized with the assistance of an eye physician and dive instructor.
For more information on vision issues, see the complete article by Frank K. Butler Jr., Captain, Medical Corps, United States Navy on High-Pressure Ophthalmology from Alert Diver.