To the Editor. —Some of the disadvantages of the use of silicone sponge in retinal surgery have been documented in a recent article in the Archives by Drs. Russo and Ruiz (85:647-650, 1971). I think that it is important that a unique advantage of this material be emphasized. Silicone sponge is the only material I have found that will produce a permanent scleral buckle without changing the patient's refraction. This is important in patients with little or no refractive error who need retinal surgery. Procedures employing silicone encircling bands usually produce 2 diopters of axial myopia. Patients who have never needed corrective lenses for distance find the induced myopia in the affected eye burdensome. Frequently, they prefer to remain uncorrected following successful retinal surgery. Normally, I use solid silicone implants with silicone encircling elements. Aphakic patients or moderately myopic individuals do not mind the 2 D of myopia that