Impaired Vision in Contact Lens Practice

Purpose. The aim of this case report is to describe the treatment of myopic eyes with pathological reduced vision. A contact lens and a spectacle lens build a telescope and the associated magnification helps to increase vision acuity.

Material and Methods. The myopic not presbyopic eyes (−3.00 D) were overcorrected by −7 D with bitoric, spherical, rigid contact lenses, base curve = 8.00/7.65 mm, back-vertex-power = −10.00/−12.00 D, over-all diameter = 10.4 mm. The refractive compensation with the spectacle lens, back-vertex-power = +6.50 D (corneal-vertex-distance 12.0 mm), front-surface-power = +7.50 D, refractive index = 1.50, over-all diameter = 65 mm, centre thickness = 7.10 mm together with contact lens build a Galilean type telescope with a maximum of magnification power.

Results. The magnification power of the telescope was Vs = 1.091, the magnification power of the spectacle lens was Ve = 1.037 and the related total magnification power was Vg = 1.131. The telescope increased the binocular distance vision acuity from 0.40− to 0.63 and the binocular near vision acuity from 0.32+ to 0.40+.

Conclusion. The Galilei system described is suitable for improving visual acuity in the case of special visual impairments.