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).
