Compare Welch Allyn Series: How to Pick the Best Light Source

This is the third installment of a series of posts on comparing Welch Allyn products that will help incoming first year medical students learn about and select different medical instrument components to construct the right Welch Allyn diagnostic kit (otoscope and ophthalmoscope). The focus of this discussion is on Welch Allyn diagnostic kit light sources, which are the physical bulbs that illuminate the ear canal or retina through the otoscope and ophthalmoscope, respectively.

Choices here are limited throughout the industry to either halogen bulbs, which have been the long-standing default in the field, or the newer sexier light-emitting diode (LED) technology. If you’re interested in the bottom-line short version, scroll to the bottom.


Welch Allyn Halogen BulbFirst let’s hit the older (read: cheaper) option that is still the default for diagnostic kits today. Halogen bulbs have been the standard for otoscopes and ophthalmoscopes for a while now, and Welch Allyn has (in their usual fashion) claimed theirs is the best. Halogen lights in general produce a yellow or off-white softer light. This actually comes in handy when viewing a retina, as brighter lights will constrict the pupil, thus making it more difficult to actually see the retina.

The downside to halogen bulbs is that they are somewhat easy to break, and they degrade and burn out faster than LEDs. Historically, halogen bulbs have cost up to $60 to replace, making this a sub-optimal option that doctors just had to put up with. Today, the price has thankfully lowered. Overall, this is now the cheaper option simply because it is the older technology, even though it works reliably well.


Welch Allyn LED Bulbs for Diagnostic KitsDiagnostic kit LED lightsaber bullets bulbs on the other hand are the more expensive option, which is somewhat surprising simply because LED technology of this variety has been around for a lot longer than it has been used in otoscopes, and should theoretically be cheaper. Welch Allyn had previously scoffed at LED lights, but are now making the transition over since competitors have been offering this option. Due to these recent changes, you can still find contradictory representatives that claim LED lights are not needed, while portions of their website claim LED lights as superior. They have however taken some time to create shiny exaggerated graphics, which I will share below. Regardless, do not be surprised if this newer option is not yet offered by most retailers.

Not quite sure how to interpret this one…

LED bulbs produce whiter and brighter light, allowing for clearer visualization of ears and noses. Check out the direct comparison of the two light sources in the top image. The LED is like a light-bazooka in comparison. Med students can just use their LED otoscope and actually forgo carrying a separate penlight to check pupils or look in someone’s throat, as they run on similar LED bulbs (that only cost the expected $2). LEDs use a fraction of the power compared to halogens (which means your handle battery lasts longer), are near-impossible to burn out, and don’t degrade in light quality during extended use. In almost every way, LED bulbs produce harder, better, faster, and stronger light.

The first real downside at this point is the cost, but that is expected to dramatically drop as soon as generic options are created that fit Welch Allyn diagnostic kits. Refuting the claim that the LED can be “too bright” is as easy as dimming the bulb on the power switch. As an aside, I find it amusing that Welch Allyn believes that dimming a halogen bulb, as seen in their demo on the right, somehow produces black-light (I said they were exaggerated). My personal solution, and the setup that I use in my instruments, is keeping the ophthalmoscope halogenated, and using an LED only with the otoscope. I get the best of both worlds. Keep in mind that you may need to open your instruments to insert the LED bulb yourself if your retailer does not provide this service for you. If you have the smarts to get into med school, this shouldn’t be too difficult to figure out. I’m sure there’s a “how many med students does it take to screw in a light bulb” joke somewhere in there.

Selecting an LED bulb may seem like a no-brainer. However, choosing this optional component in your diagnostic kit should come down to the question as whether this sexy super-light is actually needed. For the large majority of medical students, the answer is no, and the prices offered by Welch Allyn should serve as a deterrent, if the option is offered by retailers at this point.


In summary, the direct comparison is as follows:

Approx. Price Lifetime *
Color and Intensity
Halogen Bulb
$25 ~7 months Soft yellow
LED Bulb
$90 ~25 years Bright white
* refers to the total time when the bulb is actually on and in use

Still can’t decide? Let us help! Check all that apply:

My retailer doesn’t even offer LED, and I’m not really a do-it-yourself kinda person.
Money is of no concern in the purchase of my instruments.
I have a habit of dropping my cell phone frequently.
I want to learn on the same components as everyone else, including the people teaching me.
I want to learn physical exam techniques using the absolute best equipment at my disposal.
I’m never going to use this diagnostic kit after med school, and will probably not use it that much in med school either.

Suggestion:

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One Response to Compare Welch Allyn Series: How to Pick the Best Light Source

  1. Pingback: Otoscope and Ophthalmoscope Set Alternatives: Med School Supply | Med Student Books

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