• Keratoconus
• cornea

A quick Google search led to 277 000 hits for keratoconus but 18.2 m for macular degeneration. It comes as no surprise to find that the condition has a relatively low profile in the public domain, given that most ophthalmologists may see such cases only occasionally, and the condition is relatively rare. Reasonable estimates for its prevalence in the general community range from 0.004%1 to 0.055%.2 An earlier study reported a prevalence of 0.33%.3 Nevertheless, when presented, each case is an enigmatic challenge requiring the clinician to consider other areas outside the main spectrum of ophthalmology such as physiological optics, biomechanics and mathematics. Keratoconus falls under the general axiom: the rarer the condition, the greater the number of inconsistencies and controversies surrounding the condition. This view is highlighted by considering two extremes: the gender bias and life expectancy in keratoconus. Duke-Elder4 described keratoconus as ‘frequently due to a congenital weakness of the cornea though it only manifests itself after puberty, generally in girls.’ The gender bias …