I was consulting Swami AlokAnanda's translation of "AporakshAnubhuti" . Upanetra has been translated as spectacle or lenses, or any other aid for proper vision.

Prefix "Upa" is used to denote a meaning which implies something which is the nearest approximation to the word which follows the prefix. A spectacle or lens is the nearest approximation to eye , but not eye proper

In his Aparokṣānubhūti verse 81, Śaṅkarācārya says: sūkṣmatve sarvavastūnāṃ sthūlatvaṃ copanetrataḥ. Here, some modern interpreters have interpreted the word upanetra as referring to eye-glasses or some lens that enlarges the view. I am just wondering about the history of lenses and eye-glasses around the time of Śaṅkara. An allied question will be the date and authorship of Aparokṣānubhūti. Any information and references are appreciated.

Madhav M. Deshpande

Professor Emeritus, Sanskrit and Linguistics

University of Michigan, Ann Arbor, Michigan, USA

Senior Fellow, Oxford Center for Hindu Studies

Adjunct Professor, National Institute of Advanced Studies, Bangalore, India

[Residence: Campbell, California, USA]