Provided is a technique capable of detecting a stain on an opening with a simpler configuration than a conventional one. An optometry apparatus includes an observation port, a light source, a light receiving system, and a control unit. The light source is configured to irradiate the measurement light to the cornea of the subject's eye through the viewing port. The light receiving system includes a sensor that receives reflected light from the cornea through the viewing port. The control unit is configured to measure the corneal thickness of the subject's eye based on the signal waveform of the corneal endothelium and the signal waveform of the corneal epithelium included in the light receiving signal from the sensor (S130). The control unit is further configured to determine whether or not the viewpoint is dirty based on the signal waveform of the corneal endothelium and the signal waveform of the corneal epithelium (S140). [Selection diagram] FIG.【課題】従来よりも簡易な構成で、見口の汚れを検知可能な技術を提供する。【解決手段】検眼装置は、見口と、光源と、受光系と、制御部と、を備える。光源は、見口を介して被検眼の角膜に測定光を照射するように構成される。受光系は、見口を介して角膜からの反射光を受光するセンサを備える。制御部は、センサからの受光信号に含まれる角膜内皮の信号波形と角膜上皮の信号波形とに基づき、被検眼の角膜厚を測定するように構成される（Ｓ１３０）。制御部は更に、角膜内皮の信号波形と角膜上皮の信号波形とに基づき、見口が汚れているか否かを判定するように構成される（Ｓ１４０）。【選択図】図４
