Optical element having a coating for enhanced visibility of a mark and method for making the optical element

An optical element comprising:

• (a) a first coating layer over at least a portion of a surface of an optical substrate having a mark on the surface of the optical substrate;
• and
• (b) one or more additional coating layers over at least a portion of the first coating layer,
• wherein,
• the first coating layer has a first refractive index and the optical substrate and the mark have a second refractive index, and
• a difference between the first refractive index and the second refractive index has an absolute value of 0.02 to 0.24,
• wherein the one or more additional coating layers have a third refractive index, and wherein a difference between the second refractive index of the optical substrate and the mark and the third refractive index has an absolute value of less than 0.02,
• wherein the first coating layer enhances a visibility of the mark when a source of electromagnetic energy is viewed through the optical element or when the electromagnetic energy is reflected from the optical element, and
• wherein an absence of the first coating layer reduces or eliminates a visibility of the mark when a source of electromagnetic energy is viewed through the optical element or when the electromagnetic energy is reflected from the optical element.