Based on the identification by colorimetry of a colour image of the fundus of the eye of an individual, obtained by specialised cameras (fundus camera or retinograph). The method and the device of the present invention enable establishing a direct relation between the chromatic properties of the various tissues of the optic nerve (10) and the amount of haemoglobin (Hb) in the optic nerve head (10), allowing identification and clearly distinguishing the irrigated regions of the optic nerve (10) from the non-irrigated regions or those with atrophy, constituting a tool of great interest in monitoring and diagnosis of glaucomatous disease and other optic diseases affecting vascularisation. This method also allows taking into account the effect of loss of transparency of the lens in patients with cataracts, as this effect is compensated without affecting the final results of the determination of the amount of haemoglobin (Hb).
