Abstract: An ophthalmological patient interface device (27), for application onto an eye (3) during treatment of the eye (3), comprises a coupling part (21) for attaching mechanically the ophthalmological patient interface device (27) to an optical projection system (20) of an ophthalmological apparatus (1), and a fastening device (271) for fastening the ophthalmological patient interface device (27) to the eye (3). The ophthalmological patient interface device (27) further comprises a mirror system (275) arranged downstream from the optical projection system (20), when the ophthalmological patient interface device (27) is attached mechanically to the optical projection system (20), and having at least one mirroring surface arranged at an angle with respect to a projection axis of the optical projection system (20), such that a laser beam (L3) projected by the optical projection system (20) is deflected by the mirror system (275).

Abstract: An ophthalmological patient interface device (27), for application onto an eye (3) comprises a coupling part (21) for attaching mechanically the ophthalmological patient interface device (27) to an optical projection system (20) of an ophthalmological apparatus (1). The ophthalmological patient interface device (27) further comprises a firm, ring-shaped, and transparent contact part (272) configured to contact a ring-shaped peripheral surface area (B) of the cornea, when the ophthalmological patient interface device (27) is applied on the cornea, while leaving uncovered by the contact part (272) a round central surface area (C) of the cornea, surrounded by the peripheral surface area (B), and to let pass a laser beam (L1) from the optical projection system (20) through the contact part (272) into eye tissue (30) covered by the ring-shaped peripheral surface area (B) of the cornea, when the ophthalmological patient interface device (27) is coupled to the optical projection system (20).