Original 2008 owner... dash lights have become dimmer and dimmer as car has aged, not daylight etc

dimmer wheel?

 

Age. UV deterioration of coloring dyes and pigments.

 

When I got my used Prius I had the same thought. Whoever set the brightness specifications on the dashboard and MFD display must have been psychotic. I wonder if they really degrade or are just low power and brightness. I’ll never know unless I find a brand new combo display to compare it to.

 

What do you mean when you say the dash lights?

The numbers and symbols of the speedometer, odometer, fuel and PRNDB displays? Those are greenish vacuum-fluorescent segments.

The dash warning lights? Those are (in Gen 2) generally little light bulbs or LEDs, that mostly only light up for brief moments to indicate something.

The lights that illuminate the labels of buttons and switches and the shifter at night? In Gen 2, those are little bitty light bulbs that glow for hours at a time, whenever you are driving at night.

So it would be helpful to know which ones you mean.

Those illumination bulbs do get dimmer over time, as tungsten metal tends to slowly boil off their filaments and end up coating the inside of the glass bulb with a kind of gray coating. That happens faster the brighter you like to run them.

When I bought a 2008 or 2009 a few years ago, two or three of those illumination lights were already burned out, so I picked up new ones at the dealer and changed them. So if you have a 2008, it might be time for that too.

In my case, the prior owner probably had the dimmer turned way up. I prefer to drive with the dimmer set much lower (I don't like the dash lights wrecking my night vision), and that also makes a huge difference in how long those light bulbs last. In a car driven from the first day with a low dimmer setting, probably no one will ever see those bulbs burn out.

 

I thought I was clear but apparently not clear enough, I meant the green fluorescent speedometer and odo. Mine are readable but not as readable as in my other two cars.
The dimmer wheel just makes them dimmer, so it’s not that.
The various warning lights and shifter etc., IMO don’t really have to be bright, just visible and they are visible enough.
The MFD is ok as long as I use a sunshade. This is the first car that I’ve ever had to shade the dashboard to be able to read it in the daylight.
If I wear even minimal sunglasses, the odo and speedometer are prettier useless. I’ve never had that problem on other cars.
At night, no problem but most of my driving is daytime.

 

sorry to hear it

 

I got the impression Chap was replying to the OP's post, not yours.

 

Just making sure