Where false strip lashes only last one day, run the risk of lifting, and aren't necessarily tear-resistant (not to mention the possibility of mascara running); eyelash extensions last for weeks, can be completely customized to your liking, and are 100% mess-free. And the best part? You'll wake up the next day honeymoon-ready. To me, it's a no-brainer, but to fully weigh your options and make the decision that is right for you, you must consider the following:
Eyelash extensions last anywhere from two to four weeks, which means:
You don't have to worry about application the day of your wedding, as you'll most likely have them freshly applied a couple of days beforehand
They will last you through your honeymoon
You can "try them on for size" weeks prior to the wedding (which gives you time to determine whether you have any sensitivities), and can collaborate with your artist during fill or touch-up appointments to make any adjustments that may be necessary to give you the exact look you want for your special day. When beginning this process, make sure to provide your artist with inspiration images if you have them, give honest feedback about your set every step of the way, and take into consideration the makeup look that you will be wearing on the day of your wedding. This is especially important if you plan on wearing a bolder look, as you will want to have the lashes to match. Same thing for a very natural look. If you can, do a trial run with your makeup artist after getting your lash extensions done to see how well the makeup and lashes work together.
Falsies, on the other hand, require same-day application, meaning you'll have to spend more time in the makeup chair on an already-busy day; only last you the day of the wedding (that is, if they don't lift throughout the day), and not into your honeymoon; and cannot be customized in the same way that eyelash extensions can between trial runs.
While it is true that you can try multiple styles of falsies, cut them to fit your eye, and even use individual or sectioned lashes to mix and match, eyelash extensions allow for the most customization just in the nature of the application process. Because every single natural lash has an extension placed on it, the artist has the ability to create a set entirely specific to you, your eye shape, and your natural lashes. Every single extension placement is intentional during lash application, and can therefore be adjusted as needed to give you your desired look.
It is likely that on the big day, you will shed a few happy tears. You should be able to do this freely—without worrying about runny mascara. Falsies require your natural lashes to be coated in mascara for blending purposes, and even though waterproof mascara is a thing, it can still sometimes flake off and collect in the lower lash line. Not to mention that tears may mess with the integrity of the lash glue and cause the falsies to slip and slide, or worse, lift. Lash extensions eliminate the need for mascara entirely, so messy black streaks or flakes are absolutely nothing to worry about.
Comfort is a huge factor to think about on your wedding day, especially considering the fact that you already may be sacrificing it elsewhere; whether it be with your dress, shoes, hair, etc. If you're anything like me, you can feel falsies sitting on your eyelids and sticking to your skin, which isn't the most comfortable. They can also feel heavy, depending on the style. Eyelash extensions on the other hand, weigh very little (if done correctly), and can barely be felt on the lashes.
All these things considered, eyelash extensions seem to be the way to go for various reasons, but it is your call to make. Whichever you choose, please make sure you are going to an artist who has a good reputation, who is skilled in various styles so that you have the luxury of trying out different things, and who is determined to give you the exact look you want. It is your big day, after all, and you should be able to enjoy it in total confidence!