So I just bought a Elegoo PHECDA laser engraver and I was wondering how to figure out what safety glasses I would need to buy besides the green ones they provide. I believe what they gave would suffice but I’d rather have actual ones to protect my eyes. The laser it uses is a Blue laser with a wavelength of 455±5.
Note: I am really not an expert. If what I have to say conflicts with what you've heard from someone who is an expert, pay attention to them and not me.
There are three things you need to keep in mind when buying laser safety equipment:
Wavelength. Most laser safety glasses are rated for some combination of laser wavelengths. You seem to have this down already.
OD (Optical Density). This represents the strength of the protection the eyewear provides. Higher OD means greater protection.
Certification. The US, the EU, and I think Australia have standards for laser protection gear. Anything not rated by an appropriate agency in a developed country is suspect.
I have a Snapmaker 2, which comes with a blue-green diode laser with a wavelength similar to yours. Every correctly certified and rated piece of protective equipment I've come across for my laser is orange. That makes the green goggles Elegoo sent you kind of suspect—their supplier may have lied to them about the effectiveness and frequency band. These are the kind of thing you are looking for (not endorsing this specific supplier, just the first I could pull from my browser history).
Not to shill but I have been really happy with the glasses I have from laservision (lasersafety.com). You can select laser type and they'll show you what glasses make sense - they're not cheap but I have a lot of confidence in them.