A contact wear detector for a circuit breaker, the contact wear detector comprising: an electrical contact in a case of the circuit breaker, the electrical contact having a base layer composed of a first material and a contacting layer composed of a second material, the contacting layer being configured to electrically contact an opposing contact in the circuit breaker, the base layer being capable of having portions exposed through worn areas of the contacting layer, the first material of the base layer being configured to form an arc between the portions of the base layer exposed through the worn areas and the opposing contact when the electrical contact and the opposing contact separate, the arc thus formed emitting light having a characteristic optical spectrum of the first material; and an optical detector located in the case of the circuit breaker to directly receive light emitted by the arc, the optical detector being configured to detect the characteristic optical spectrum of the light emitted by the arc between the portions of the base layer exposed through the worn areas and the opposing contact, wherein the first material of the base layer is composed of multiple materials that have mutually distinctive optical spectra, so that there is a gradual change in composition of the first material of the base layer being eroded by arc erosion, characterized in that the optical detector is connected to adjustment and tuning circuitry to tune the optical detector to detect the light having the characteristic optical spectrum of the first material of the base layer and to fine-tune the sensitivity of the optical detector. an electrical contact in a case of the circuit breaker, the electrical contact having a base layer composed of a first material and a contacting layer composed of a second material, the contacting layer being configured to electrically contact an opposing contact in the circuit breaker, the base layer being capable of having portions exposed through worn areas of the contacting layer, the first material of the base layer being configured to form an arc between the portions of the base layer exposed through the worn areas and the opposing contact when the electrical contact and the opposing contact separate, the arc thus formed emitting light having a characteristic optical spectrum of the first material; and an optical detector located in the case of the circuit breaker to directly receive light emitted by the arc, the optical detector being configured to detect the characteristic optical spectrum of the light emitted by the arc between the portions of the base layer exposed through the worn areas and the opposing contact, wherein the first material of the base layer is composed of multiple materials that have mutually distinctive optical spectra, so that there is a gradual change in composition of the first material of the base layer being eroded by arc erosion, characterized in that the optical detector is connected to adjustment and tuning circuitry to tune the optical detector to detect the light having the characteristic optical spectrum of the first material of the base layer and to fine-tune the sensitivity of the optical detector.