• An oversized, negative-power spectacle lens may be used as a field expander to improve mobility and general orientation ability of patients with peripheral field loss but intact central vision. The device is inexpensive and simple to use for brief spotting periods.
Kozlowski JMD, Mainster MA, Avila MP. Negative-Lens Field Expander for Patients With Concentric Field Constriction. Arch Ophthalmol. 1984;102(8):1182-1184. doi:10.1001/archopht.1984.01040030960025