Twice a day near the equator the sun sits exactly where you are looking, low and blinding. In Vietnam the geometry is worst on east-west roads at rush hour: the same sun that is blinding you is also blinding every driver heading the other way — and they cannot see you either.
If you cannot see, assume you are not seen
When the sun is behind you, oncoming drivers squint into glare and lose small silhouettes like motorbikes first. Your headlight makes you wider and brighter; visibility-riding-motorbike-vietnam explains why being seen is a tactic, not luck. Slow down and expect oncoming vehicles to drift.
Adjust your eyes and your speed
A tinted visor or good sunglasses helps you see, but every time you enter shade you are briefly half-blind — flip the visor up approaching tunnels and tree-shaded streets rather than mid-shade. eye-protection-riding-motorbike-vietnam covers eyewear choices in Vietnam’s light.
Never outrun your sightline
The rule from fog applies to glare: ride at a speed where you can stop in the distance you can actually see. Glare makes roadside hazards, pedestrians and potholes invisible until the last metres — see fog-and-low-visibility-riding-motorbike-vietnam for the same discipline with different lighting.
The Hanoi commuter window
Sunrise and sunset align with rush hour, so the road is dense exactly when vision is worst. Leave earlier or later if you can, and where the route runs east-west with the sun dead ahead, pick a parallel street with tree cover — old Hanoi streets were planted for exactly this.
The general defence
Glare is a reminder that being predictable is the rider’s armour: lights on, steady lines, generous space. Defensive-riding habits — defensive-riding-motorbike-vietnam — carry the day when everyone’s eyes fail at once.