DIY Night Vision

Typically my cycling season starts and ends with the change of daylight savings time.  In the past, when I have extended the cycling season past this time I end up riding in the cold, wet, and dark.  These variables are manageable but other elements present an unacceptable hazard.  Automobiles at night can blind you with their headlights.  Many approaching motorists will leave their brights on long after they notice you coming towards them with your bike lights on.  Don’t they realize that a cyclist requires vision as much or more than an oncoming motorist?  There’s a reason they call it “the deer in the headlights look”.  I have a DIY lighting system with high beams that will give the oncoming car a dose of their own medicine but that is the subject of another post.  Instead, I will describe another more effective way of mitigating the headlights of an oncoming car — a tilt-down headlight filter made from a Nalgene-style water bottle.  Last year my wife sacrificed her green Camelback water bottle for the prototype.  The prototype worked great and I expected to use it again this winter.  About a month ago my mountain bike helmet fell off the shelf and the filter broke.  I nearly cried.  Oh well, this allows me to document the process for making a new one.  I even have enough leftovers from the old donor bottle to make a second one.  I’m sure Shaunna is relieved to hear this.


Figure 1:

  • bike helmet
  • helmet visor (detached)
  • template ( cut from soda can)
  • marker
  • bowl of soda can cuttings
  • scissors for cutting template
  • Nalgene-style water bottle ( darkest colors makes a better headlight filter)

Used but not shown:

  • painters masking tape
  • drill
  • Dremel tool w/ cutoff wheel
  • zip tie (only one with this visor)
  • 6″ of foam weather stripping

Missing in the images:

  • marking & cutting the template to match helmet front
  • cutting of water bottle using dremel tool w/ cutoff wheel

Figure 2:

  • mark holes to be drilled for attaching filter to visor.
  • allow a 1/4″ gap between helmet and filter.


Figure 3:

  • drill holes in filter to allow zip tie attachment

Figure 4:

  • cut and affix weather strip to filter between zip tie holes.

Figure 5:

  • thread zip tie from thru holes in filter and visor (start from hole under filter nearest helmet)
  • tighten zip tie & clip excess


Figure 6:

  • close-up of zip tie from top


Figure 7:

  • bottom view of attached filter.

Figure 8:

  • adjust hemet on head and place painter’s tape to set cut-line.
  • establish the cut-line by tilting helmet down until you can see oncoming headlights just below the visor and above tape.
  • filter should only extend about 1½” below the visor.
  • cut off filter using top of tape edge


Figure 9:

  • smooth the edge of filter w/ Dremel tool using drum sander
  • headlight filter is done.

This headlight filter has served me well when riding at night.  Even in the direct headlights of an oncoming car, I can make out the edge of the shoulder and potholes in the road.

No more “cyclist in the headlights look” from me.

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