Optical film, polarizing plate, and image display device

An optical film comprising a resin base material and a functional layer provided on a first surface of the resin base material,

• wherein a front surface of the optical film constitutes a front surface of the functional layer;
• the absolute value of the difference in the arithmetic mean height of a 5-μm square region on the front surface of the optical film measured using an atomic force microscope between before and after a rubber eraser abrasion test is 10 nm or less when the rubber eraser abrasion test is performed by rubbing the front surface of the optical film 5,000 times with a rubber eraser in a reciprocating motion under a load of 1,000 g;
• a 5-μm square region on the front surface of the optical film is observed to have 1 or more and 50 or less depressions having any shape at least selected from a ring shape with an outer diameter of 0.1 μm or more and 2.5 μm or less and with a depth of 1 nm or more and 150 nm or less, a circular shape with a diameter of 0.1 μm or more and 2.5 μm or less and with a depth of 1 nm or more and 150 nm or less, and an irregular shape with a width of 0.1 μm or more and 2.5 μm or less and with a depth of 1 nm or more and 150 nm or less, when the square region is observed using an atomic force microscope after the rubber eraser abrasion test;
• the front surface of the optical film has a dynamic friction coefficient of 0.70 or less measured using the rubber eraser under a load of 1000 g before the rubber eraser abrasion test;
• and
• the change rate of the dynamic friction coefficient of the front surface of the optical film measured using the rubber eraser under a load of 1000 g after the rubber eraser abrasion test to the dynamic friction coefficient of the front surface of the optical film before the rubber eraser abrasion test is up to 35%.