To easily observe a patient and aiming light immediately before application of treatment laser light by driving a filter for cutting treatment laser light under a wearer's very nose to open and close, and controlling the opening and closing drive of the filter according to emission of treatment laser light from a laser treatment device.

A protective filter 10 is installed to be opened and closed in the direction of A taking a shaft 1 as a rotating shaft between ear holding parts 12a, 12b extended from a goggle frame 13, and a small-sized rotary solenoid 21 is disposed in the interior of an opening and closing operating part 11 for driving the protective filter 10 to open and close. The opening and closing operation of the protective filter 10 is conducted by the rotary solenoid 21, and in opening, it is positioned substantially at right angles to the goggle frame 13. When the protective filter 10 is closed by the drive of the rotary solenoid 21, it abuts on the goggle frame 13. Thus, a patient and aiming light can be easily obserbed immediately before application of treatment laser light.