An optical accessory, which can be associated with a mobile device such as a smartphone or tablet, is described. The accessory comprises coupling means which allow it to be firmly positioned in correspondence with both a camera lens and a light source of the mobile device. The optical accessory further comprises a first optical element provided with a first reflective surface, for example a mirror. The mirror surface reflects a source light beam emitted by the light source and generates a first reflected beam directed toward the visual field of the camera lens. Moreover, the accessory comprises a second optical element, i.e. a beam splitter, provided with a partially reflective second surface, generating a second reflected beam directed to illuminate the eye of a patient and substantially inside the visual field of the camera lens so as to realize an ophthalmoscopic system which allows the examination of the “fundus oculi” of the eye.
