Long-term acceptance of prisms by heterophorics.

Forty-six heterophoric clients with long standing severe visual symptoms were corrected with prisms for permanent wearing using the full-correction procedure of Haase. With 80% of clients the prism power had to be increased one or more times until a permanent correction power was reached. With all clients permanent powers were attained, basic optometric functions were improved and subjective complaints were reduced. The correction status and improvements were maintained during long term follow-up.