In this study we examined refractive changes of 34 eyes in 34 patients treated with silicone oil injection. Six patients presented with aphakic retinal detachment, another 14 were rendered aphakic after silicone oil injection, one was pseudophakic and 13 were still phakic at the time of writing this report. Silicone oil in the vitreous cavity induced a myopic shift in aphakic eyes and a hypermetropic shift in phakic eyes. This tended to render phakic high myopes and aphakes closer to emmetropia. The resultant refraction was dependent on the shape of the silicone oil bubble inside the eye and influenced by the posture of the patient. In phakic patients the ability to accommodate was markedly reduced.