Prospective study of the new diffractive bifocal intraocular lens.

The visual results of 55 bifocal lens implantations are compared with 55 matched PMMA monofocal implantations. 84% of the eyes with bifocal implants compared with 20% of the eyes with monofocal implants could read N8 or better with the distance correction (p less than 0.001). 52% of +/- 3.5D bifocal eyes could read N5 with the distance correction. The mean reading addition for a near point of 25 cm was 0.3D in the bifocal group and 2.2D in the monofocal group. 20% of eyes with bifocal implants could not be corrected to N5 at a comfortable distance (p = 0.005). It was found that the clear advantages of this bifocal lens must be countered in a minority by a loss in quality of vision particularly for reading.