Couching

Couching is an ancient ophthalmic procedure once used to treat cataracts by displacing the cloudy lens from the visual axis into the vitreous body of the eye. The technique aimed to restore some degree of vision by removing the lens from the line of sight, though the natural lens remained inside the eye.

The method is described in early medical literature, most notably in Indian sources such as the Sushruta Samhita dating to around the sixth century BCE, with analogous accounts in Persian and Chinese medical texts. The term couching derives from the sense of laying down or embedding the lens out of the visual path.

In practice, a fine needle or similar instrument was inserted through the cornea toward the lens. A deliberate tapping or pushing motion displaced the lens into the vitreous cavity behind the iris. Outcomes varied, and success depended on factors including the cataract’s density, the eye’s anatomy, and the surgeon’s skill. Some patients experienced temporary improvement in vision, while others had limited benefit or none at all.

Couching carried significant risks, including chronic inflammation, glaucoma, retinal detachment, infection, and persistent visual impairment. Because the lens was not removed, many patients developed long-term complications, and some required additional eye procedures.

Couching declined with the development of modern cataract surgery, including intracapsular and extracapsular extraction and, later, phacoemulsification with intraocular lens implantation. Today, couching is regarded as a historical technique that illustrates early efforts to restore sight and the evolution of ophthalmic surgery.