Vitreous opacities, or floaters, are common ocular conditions in retinal practice. Although symptoms are minimal in most patients, they can significantly impair the quality of life in some patients, especially those who have multifocal intraocular lenses. They can even cause psychological problems in some cases. In recent years, small-incision (25-G, 27-G) vitrectomy surgery has become the preferred approach for symptomatic vitreous opacities. However, appropriate patient selection is often difficult due to the lack of adequate, objective tests to measure both preoperative deterioration in the quality of vision and postoperative improvement in vision.