RT Journal
A1 PASCAL JI
T1 SUiting the cylinder to the mirror in retinoscopy
JF Archives of Ophthalmology
JO Archives of Ophthalmology
YR 1941
FD August 1
VO 26
IS 2
SP 265
OP 267
DO 10.1001/archopht.1941.00870140115008
UL http://dx.doi.org/10.1001/archopht.1941.00870140115008
AB Retinoscopy can be practiced with either a plane or a concave mirror. Of the latter there are two types, the usual short focus concave and the occasionally used long focus concave. With the latter the light directed to the patient's eye is convergent, but to a relatively slight extent. It must be used so that the light tends to focus behind the patient. Unless one is very careful the incident convergent light, instead of focusing behind the patient, may tend to focus in the plane of the patient's eye (strictly speaking, in the plane of the pupil). This leads to a confusing phenomenon, for in this case no motion is observed whatever the condition of the patient's eye. It gives rise to what may be called the "incident neutral point." For there is a neutral point for the incident light, just as there is one for the emergent light. This