Fig 6. Comparison of preoperative laser and letter acuity in patients with cataract (dark boxes) and corneal opacities (light boxes). (From Green DG, Cohen MM: Laser interferometry in the evaluation of potential macular function in the presence of opacities in the ocular media. Trans Am Acad Ophthalmol Otolaryngol 75:629, 1971 and Gstalder RJ, Green DG: Laser interferometry in corneal opacification. Arch Ophthalmol 87:269, 1972.)