Corneal innervation is an increasingly exciting avenue in medicine. Examining the innervation of the cornea is beginning to be applied in new ways to understand ocular-specific and systemic diseases, from diabetes to cancer. 

As the body’s most sensitive tissue, the cornea is the most densely innervated part of the body (Yang et al, 2018), receiving innervation solely from nociceptive neurons (which cause us to sense pain after physical damage). Sensory nerve endings in the corneal epithelium have a density around 400 times greater than those in the epidermis of the skin, with approximately 7,000 nociceptors per square millimetre in the cornea (Remington, 2012).