[The low vision cyclist: handicapped orientation and assessment with the nystagmogram]

Visually impaired individuals who are unable to obtain a driving licence may use a bicycle and feel fit for traffic as part of this "bio-physical model".

Five nystagmic amblyopes who claimed to ride a bicycle were tested in respect to visual acuity, peripheral vision and oculomotor functions. In three of these cases visual acuity amounted to 0.3, in one to 0.6, in another one only to 1/35. Eye movements were recorded by electro-oculography. The following qualities of gaze were determined: Fixation-saccadic eye movements-pursuit eye movements-behaviour in light and dark-vestibulo-optokinetic movements-eye positioning in resting states and influence of mood.

In four of the cases oculomotor regularities were found. These were explained to the patients. One of the cases was affected with a form of chaotic nystagmus.

Bicycling demands on both the vestibular and the visual system. Deficiencies relevant to behaviour in traffic and the possibilities to compensate for these may be estimated based on a oculographic evaluation. This should therefore be used to advise bicyclists with a visual impairment.