Play it Safe
If you have any gear indication problems, you should immediately exit from the landing phase, execute a go-around, advise ATC, with permissions climb to a safe altitude above MSA away from the airport, turn on your landing lights, put the aircraft into a hold or fly a triangle on heading and time. Watch your fuel. One pilot to do the visual inspection via the viewers, the other must fly the airplane. If it is not possible to view the downlock indicator, you must arrange a flyover inspection at nearest suitable airport. If the gear is not down, follow handbook procedures for gear up landing. You must not retract the gear for a second try, unless your procedures say otherwise, as the outcome is unpredictable. A broken walking beam on a 737 could, for instance, snag the roll-spoiler cables. You don't want to be in a situation where no one is flying the aircraft or adding extra complications because you decided to experiment. If you can fly the airplane leave experimenting off the agenda. Always carry enough fuel for such an event (normal trip plan).