It is and it isn't at the same time

The first thing is to decide is which housing you want. Virtually all housings use PVS-14 objective lenses but some will let you re-use the ANVS objective lenses. The threads are different so you must select a housing made for ANVS if you will re-use the ANVIS-9 lenses.

The most functionally direct swap without having to buy PVS-14 lenses is the AB Night Vision RNVG (ANVS version) as it is a fixed bridge housing like what you currently have. The RNVG does add some extra features but more importantly there is not a ball-detent interface version meaning you will have to get a dovetail helmet mount such as the Wilcox G24, Norotos LoSo, etc. Nocturn Industries has a Katana ANVIS 6/9 which is a articulating housing. There are more housing options to choose from if you go with PVS-14 lenses such as DTNVS, DTNVS-MG, Manticore-R, RNVG-A. Pretty much all housings are going to lose the ball-detent interface except for the TNVC Artemis ANVS version BUT the Artemis requires PVS-14 lenses.

Most of the folks who decide to stick with ANVS lenses due so to skip the extra cost of having to buy PVS-14 lenses, however, some do prefer the image of ANVS lenses. I personally love the ANVS’ finer focus capability and like the image of the NVIS filter (lens coating). The drawbacks of using ANVS lenses are that they block red and green light wavelengths (this is for use with NV specific cockpit lighting) and they are more expensive to replace if damaged. The image is slightly darker compared to PVS-14 lenses.

The ball-detent interface is a love it or hate it kind of deal and the majority of users prefer the dovetail interface. The ball-detent does have quirks such as you can get the interface jammed up and stuck in the mount and it is a break away interface by design. Myself, I prefer ball-detent, and that’s what I run for the dead reliable auto-off/on when stowing/deploying the goggle. The goggle I use is the TNVC Artemis ANVS version.

The swap process itself is fairly straightforward if you are mechanically inclined and especially if you have the right NV specific tools (you can find them online such as on eBay). Of course, a skilled & experienced technician will do a superior job properly cleaning, inspecting, the housing, lens cells (lubricating the o rings), setting the diopters properly, collimating, purging, etc.

Properly collimating them at home can be difficult and you won't be able to purge the system. There are DIY collimation techniques that can be effective but having a vendor do it with the right equipment yields the best results.

With all of that said - if you like the goggle as it is now and you’re not doing extreme stuff with it then I would just run it as is. I ran ANVIS-9 goggles (two different sets) for quite some time and it is one of my favorite goggles - super simple (KISS), superior auto-off/on functionality, lightweight, and a very short bridge which makes it easier to look under/around the pods. I did damage one from an accidental drop but was able to repair it myself with epoxy. Keep it on a lanyard and it will hold up for a long time.

And if you want to upgrade housings we can help you out with that

Here’s a couple of relevant threads

https://www.ar15.com/forums/armory/ANVIS-housing-options-/18-551030/

https://www.ar15.com/forums/Armory/First-Dual-Tubes-Anvis-6-9-now-decisions/18-512118/