A SIMPLE, portable, lightweight perimeter has been devised, small enough to fit into one's shirt pocket, and yet accurate to a degree simulating the results obtained by the use of large fixed perimeters (eg, the Ferree-Rand, Aimark models). This instrument is less than the size of a package of cigarettes and can be used at a patient's bedside or in clinic, or on home visits, as well as in the office (Fig 1). Precise quantitative visual field measurements are easily obtained and then recorded on a visual field pad provided with the instrument (Fig 2). In addition, the perimeter can be used, as in large perimeters, for strabismometry (by Javal's or Charpentier's method), measurement of angle kappa, motor field monocular rotation measurements, and also for location of retinal tears (as is sometimes done with the Schweigger-Hand perimeter).
The instrument itself consists of a handle attached to a frame. The handle
Cohen SW. A Pocket Perimeter. Arch Ophthalmol. 1971;86(2):186-188. doi:10.1001/archopht.1971.01000010188012