These days, there’s no reason to fumble around in the dark. The market is full of flashlight choices, and many of them are far more technologically advanced than lights that were available just a few years ago, especially those that use light-emitting diodes (LEDs) and exotic gas-filled bulbs. The catch is making the right choice for your outdoor lifestyle.

If you don’t want to buy a new flashlight, both LED and Halogen/Xenon/Krypton bulbs are now available as replacements for most standard flashlight bulbs. Two sources on the internet are and

Which batteries?
Some lights are chambered for either AA or AAA cells, giving you no choice because the manufacturer specifies one battery type or the other. Others
are configured for CR123A lithium batteries only. But if your lights do
give you a choice between alkaline and lithium batteries, here’s what you need to know about their different characteristics.

Alkaline Pros: Alkaline batteries have a sloping discharge curve, so a flashlight powered by these cells will tend to go dim toward the end of the battery life. This is not all bad, because it gives you a warning that it’s time to change the batteries before your world suddenly goes black. They are less expensive than lithium batteries and they are widely available. Cons: Their shelf life is good, but not great. Al­kaline batteries do not perform well in low-temperature situations.

Lithium Pros: Lithium batteries have a very flat discharge curve, providing a steady voltage right up to the end. Lithiums deliver power two to four times longer than their alkaline counterparts, have an exceptional shelf life and are especially well suited to cold-temperature operation. Cons: When the battery dies, the light dies without warning.
Which bulbs?**
The heart of a flashlight is the bulb, though not all bulbs are created equal. Incandescent bulbs are cheap, but they produce a fairly dim, yellowish light. They also have short lives, die easily when abused and drain batteries pretty quickly.

The Brightest Lights: Halogen, Xenon and Krypton bulbs bore through the night with focused beams that penetrate up to four times farther than standard bulbs. The bulbs’ filaments send powerful illumination through focusing lenses, concentrating the beam. These bulbs last several times the life­span of a standard bulb, but they do have a filament so they’re vulnerable if dropped. They’re also relatively power-hungry and get very hot. So hot, in fact, that some flashlights have warnings printed on the surface near the bulb.

The Longest Lasting: If you want brilliant light, long life, rugged durability and optimum energy efficiency, LED bulbs are the champs. Typically rated for 100,000 hours (more than 11 years if the light is on 24/7), LEDs have no filament to break and consume very little power because all of the energy goes into creating light, not heat. The traditional drawback with LEDs is that although they are outstanding for near-distance illumination, they do not project light very far. However, with more diffuse light you don’t feel like you’re walking in a tunnel. Performance is ramping up quickly, and some LED units are now beginning to push aside their incandescent brethren when it comes to light penetration.

See in the Dark
The human eye contains light-sensitive rods and cones. When adapting to a dark environment after exposure to bright light, the cones can attain maximum sensitivity in 5 to 7 minutes, but the rods take as long as 30 to 45 minutes of absolute darkness to become fully acclimated. This is when night vision becomes effective.

Be careful not to expose night-acclimated eyes to bright light again, or night vision will be lost in seconds. To maintain some night vision when bright lights cannot be avoided, close or cover one eye. Night vision is an independent condition in each eye, so protecting one eye from the light will maintain it in that eye.