THIS publication contains the description of an optical instrument with which it is possible accurately to observe and examine the retina, as well as the images of luminous objects which may be projected upon it in the living eye. To be of value, such an instrument must overcome two important problems. First of all, as we observe the normal eye its anterior appears to be completely dark. The reason for this, as I shall demonstrate, is that under ordinary circumstances the refractive media of the eye prevent us from observing illuminated portions of the retina through the pupil. Therefore, it was necessary to devise a method to illuminate adequately that part of the retina seen through the pupil. Second, only by looking through the refractive media can we visualize the background of the eye. The phenomenon of refraction projects images of retinal structures in such a way that they cannot be visualized. It is necessary to have a special
VON HELMHOLTZ H. DESCRIPTION OF AN OPHTHALMOSCOPE FOR EXAMINING THE RETINA IN THE LIVING EYE. AMA Arch Ophthalmol. 1951;46(5):565–583. doi:10.1001/archopht.1951.01700020578016
Ophthalmology in JAMA: Read the Latest
Customize your JAMA Network experience by selecting one or more topics from the list below.