Description

Scheerer’s blue field entoscope

Scheerer’s blue field entoscope allows visualization of the paravoveolar capillaries, moving blood cells and vitreous opacities.

Ophthalmologist, Richard Scheerer , in 1924, described the ability of people to see moving clear objects in their vision when a certain wavelength of blue light was shone in the eye.
These objects are white blood cells moving through capillaries near the macula of the eye.

This became known as the blue field entoptic phenomenon or Scheerer’s phenomenon.

Apparently this device was designed to demonstrate this phenomenon.