The human eye contains aqueous humor, which separates the external cornea and the internal iris-lens structure. It is hypothesized that, in some individuals, small flakes of pigment are intermittently liberated from the iris and migrate to, and subsequently damage, the cornea. Approximating the geometry of the enclosure formed by the cornea and iris-lens structure as a pair of concentric hemispheres of outer radius ro = 10 mm and inner radius r; = 7 mm, respectively, investigate whether free convection can occur in the aqueous humor by evaluating the effective thermal conductivity ratio. K_off/k If free convection can occur, it is possible that the damaging particles are advected from the iris to the cornea. The iris-lens structure is at the core temperature, T_i = 37°C, while the cornea temperature is measured to be T_o = 34°C. The properties of the aqueous humor are p = 990 kg/m³, k = 0.58 W/m ∙ K, c_p = 4.2 x 10³ J/kg ∙ K, μ = 7.1 x 10^-4 N ∙ s/m², and 13 = 3.2 x 10^-4 K^-1.

Iris Aqueous humor Vitreous humor Lens Suspensory ligament Retina Cornea Ciliary muscle Optic nerve Iris