Question: Was travelling on a Airbus A320 (night flight) and during the safety briefing noticed that the fluorescent floor lighting strip referred to in the evacuation instructions was totally absent. Both sides of the aisle. 

I could see the marks on the floor carpet where it must have been earlier tacked on. Was removed and went unreplaced for whatever reason. 

Is it OK for an aircraft to fly without this item? Seemed pretty essential to me for a safe evacuation in the dark. 

Edit: I did try & take a photo but unfortunately didn't come out so well. 

![enter image description here](https://i.stack.imgur.com/hPf7r.jpg)

Answer: 
According to [this document](http://fsims.faa.gov/wdocs/mmel/a-320%20r21.pdf) the answer would appear to be no if all lights were missing.

![enter image description here](https://i.stack.imgur.com/vj58n.png)

The 1/1 columns indicates the number installed and required for dispatch.
Those lights don't have to be mounted to the floor. They can also be seat mounted. 

<http://www.bruceind.com/index.php?option=com_k2&view=item&id=90:escape-path-lighting-systems&Itemid=189>

<http://www.astronics.com/_images/aircraft-safety/EPM%20033010.pdf>

![Seat mounted escape path lights](https://i.stack.imgur.com/8FvPa.png)

This is the AC that provides guidance on the requirements of the system. <http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC25.812-1A.pdf>

The regulation is [14CFR 25.812](http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&SID=67a8813bf9d9da0aa64e74e2e5ced957&rgn=div8&view=text&node=14:1.0.1.3.11.4.178.62&idno=14 "14CFR25.812")