In the first, owing to congenital abnormalities, the eyes usually tend upward and the individual must go about with his chin on his chest, so that his eyes may look in front and yet remain in the position of rest. In the second, the chin is held in the air and the body arched backward. But, unless extreme, neither of these conditions causes more than cosmetic difficulty and both should be undisturbed owing to the extreme difficulty of securing the same operative effect on both eyes. Suitable prisms are much more likely to be beneficial. [Illustration: Supports for Holding The Ski-optometer _Floor Stand_] [Illustration: _Wall Bracket_] [Illustration: _Chair Clamp_] [Illustration: _Chair Attachment with Upright_ Choice may be made from any of the above. The Wall Bracket is recommended, unless refractionist is provided with a specialist’s chair, to which the Chair Attachment with Upright may be attached.]