A new device to be used with the binocular indirect ophthalmoscope is presented. It consists of a fixation target attached to the +20 diopter lens. It may be used to study the behavior of fixation and establish the diagnosis of eccentric fixation.
Hilton GF. The Diagnosis of Eccentric Fixation With the Indirect Ophthalmoscope. Arch Ophthalmol. 1969;81(5):650-652. doi:10.1001/archopht.1969.00990010652009