Optical film, polarizing plate, surface plate for image display device, and image display device

An optical film comprising an UV-absorbing layer containing an UV-absorbing agent B on a plastic film containing an UV-absorbing agent A, wherein the plastic film is a polyester film, and the optical film satisfies the following condition 1:

• <Condition 1>
• a vertical direction with respect to a plane of the optical film is defined as 0 degrees;
• a surface of the optical film on the plastic film side is irradiated with excitation light having a wavelength of 365 nm from a direction of +45 degrees with respect to the vertical direction using a spectrofluorometer, emitted fluorescence from the plastic film is measured from a direction of −45 degrees with respect to the vertical direction, and a sum of intensities of the fluorescence from 380 nm to 490 nm is defined as BL1;
• a surface of the optical film on the UV-absorbing layer side is irradiated with excitation light having a wavelength of 365 nm from a direction of +45 degrees with respect to the vertical direction using a spectrofluorometer, emitted fluorescence from the plastic film is measured from a direction of −45 degrees with respect to the vertical direction, and a sum of intensities of the fluorescence from 380 nm to 490 nm is defined as SL1;
• and
• under the foregoing premises, BL1 and SL1 satisfy the following formula (1):
• SL1/BL1≤0.30 (1).