OBJECTIVE To determine the best technique for implanting a hypernegative intraocular lens (IOL) in the posterior chamber of phakic eyes to neutralize high myopia and its results. METHODS Robert Koch Hospital, Hannover-Gehrden, Germany. METHODS We implanted the Chiron-Adatomed silicone myopia IOL in 69 eyes of 37 patients between June 1992 and August 1994 and followed them prospectively. RESULTS To avoid marked decentration, the IOL should merely touch the ciliary sulcus. Its best length should equal the horizontal diameter of the cornea (white to white). Iritis from implantation trauma was avoided by intravenous administration of 250 mg prednisone preoperatively. When inserting the Chiron-Adatomed myopia IOL, we avoided putting pressure on the crystalline lens with the spatula. In 53 eyes, the difference between precalculated postoperative refraction and achieved postoperative refraction at 3 months was +0.07 +/- 1.05 diopters (D) (mean +/- SD). No eye deviated more than 2.80 D. Eleven of 69 eyes had a follow-up of fewer than 6 months and 13 had marked preoperative cortical opacities. Eight of the remaining 45 eyes with clear or almost clear cortexes showed a central subcapsular opacity after 1 to 2 years, probably IOL induced. CONCLUSIONS Use of the Chiron-Adatomed IOL should be confined to older patients with early cataract until its role as the cause of opacities has been clarified by further observation.