Common myths about LED bulbs

LEDs never get warm, switching them often ruins them, they all harm your eyes — which of these ideas hold up and which are half-truths.

LED bulbs moved into everyday life quickly, and a lot of opinions came with them. Some are impressions left over from early LED products, some come from misread marketing, and some are partly true. Below are the claims heard most often and what actually lies behind them.

Two claims about heat and brightness

‘LED bulbs don’t get hot at all’ is partly wrong. An LED does not reach the hundreds of degrees of an incandescent filament, and the bulb will not burn your hand the way an old glass bulb could. But part of the electrical energy still turns into heat. That heat builds up behind the chips and in the driver and has to leave through the body of the lamp. On a higher-power LED bulb, the aluminium part can feel distinctly hot after running for a while.

The practical point: LED bulbs need air too. In small, fully enclosed shades heat accumulates, and that directly affects how long the bulb lasts.

‘More watts means more light’ is not reliably true among LEDs either. Two bulbs with the same wattage can give different amounts of light, because efficiency depends on the chips, the optics and the driver. Brightness is shown in lumens. When comparing two bulbs in a shop, look at lumens first and watts second.

‘Switching LEDs on and off often wears them out’

This idea was carried over from fluorescent lamps. In fluorescent and compact ‘energy-saving’ lamps, every start wears the electrodes, so frequent switching shortens their life. LED chips have no such mechanism. The driver sees a brief load each time the switch is pressed, but in normal household use this is not considered a deciding factor. For hallways, storerooms and bathrooms, where lights go on for short periods, LED is actually a good fit.

Flicker and eye health

On the claim that ‘all LED bulbs flicker’: flicker depends on the driver. Bulbs with very simple drivers can keep a ripple linked to the mains frequency; it may be invisible, yet some people find it tiring. A good driver smooths the current. A simple check: point a phone camera at the bulb, and if you see bands rolling across the screen, there is flicker. Test the specific bulb instead of generalising.

The claim that ‘LED light damages your eyes’ is about blue light. Since white LEDs start from blue chips under phosphor, some blue is always present in their light. But blue light is also part of daylight, and there is no generally accepted evidence that a good-quality bulb at normal household brightness harms the eyes. The real issues are different: staring into a bare, bright chip, flicker, and very cool light late in the evening, which can affect sleep. Choosing warm white and a bulb with a diffuser for evening use removes most of these worries.

Light colour and where LEDs can be used

The idea that ‘LEDs only give cold, bluish light’ comes from the first generation of LEDs. Today LED bulbs are sold across a wide range, from warm white (about 2700–3000 K) to cool white. Filament-style LED bulbs even reproduce the look of an incandescent lamp.

As for ‘LEDs don’t work in chandeliers or with dimmers’: E14 candle and filament LED bulbs for chandeliers are widely available. The dimmer point is true, but only partly: a non-dimmable LED bulb will not behave properly on a dimmed circuit. A bulb marked as dimmable, used with a dimmer suited to LED loads, works normally.

A related idea is that ‘an LED uses so little that leaving it on costs nothing’. Consumption really is lower than with an incandescent bulb, but it is not zero. A dozen lights left burning all night in an office or a stairwell still add up over a year. Low consumption is a reason to choose LED, not a reason to stop switching lights off.

How to test a claim yourself

Whenever you hear a new claim, look for three answers: which lamp technology is it really about (LED, fluorescent, incandescent); what does the box of the specific bulb say; and can a simple check — the camera test, touching the body, comparing lumens — confirm it? More often than not, the myth either belongs to an older technology or takes a flaw of one poor model and applies it to every LED.

Zaferoğlu Elektrik has been making LED bulbs in Ganja under the Zəfər İşığı name since 2021. If you have a question about a particular model, the product’s technical information is a better guide than general opinion.