Such electrically conductive coatings are used in flat panel computer displays and similar display devices for their high electrical conductivity and high luminous transmittance. Architectural glass, coated with ITO blocks harmful infrared solar radiation. On aircraft and automobile windshields it allows the glass to be electrically heated for defrosting or deicing without obscuring visibility. It then has the added benefit of reducing infrared transmission through the glass. Indium is used in low melting eutectic alloys for fusible links, solders, and temperature indicators.
Indium lends several desirable properties to solders, where it can replace lead.
Indium-based solder alloys are less likely to crack due to thermal fatigue. When soldering to gold or gold plated surfaces, some solders have a tendency to attract the gold into the joint, which can weaken or disrupt the plating and adversely affect the joint. The addition of indium to the solder reduces this tendency. Small additions of Indium to other pure metals or alloy systems can make the resulting alloy stronger and harder. In dental fillings, indium also reduces shrinkage of the filling material upon solidification, so it doesn't pull away from the tooth and leave a gap where bacteria and acids can get in to attack the tooth.