Muller provided a "glass shell" lens to treat which condition?

The "glass shell" lens developed by Müller is specifically designed to address the condition of loss of the upper eyelid, also known as ptosis or upper eyelid disfigurement. This innovative lens acts as a prosthetic device that helps to cover and protect the eye while providing cosmetic enhancement to individuals who have experienced loss of eyelid function or structure.

By providing a barrier, the glass shell lens not only aids in protecting the ocular surface but also helps in maintaining the eyes' appearance, thereby improving the quality of life for those affected. This particular approach was not developed for refractive errors such as myopia or presbyopia, nor does it directly treat conditions like severe dry eye, which are typically managed through other therapeutic interventions.