I took part 3 in September 2019 and had to retake, so I took it and passed on my second attempt in January 2020. I believe it comes down to three key components:
1. Skills
Practice as much as you can. Make sure you practice as if you were taking the actual exam every single time. Even practice pressing the online timer each time. Follow the rubric and read all the candidate guides and online tutorials. We all know how to do the skills, but can you do them exactly as the rubric says? If you can practice in a NBEO room at an optometry school, that's even better. Try to go over each station at least 3 times, each time as polished as if you were to do it that way on the actual boards exam. Record yourself practicing (on voice) so you know how much time is left, and then you can re-listen to each attempt to see if you hit every point on the rubric.
2. Script
Know your script inside and out. Perfect your script. Double- and triple-check your script. Add to it and change it every time you practice and realize how it could be improved, or when your classmate points out how you could improve something. Record a version of your script including all stations and listen to it on long drives, flying and when you have free time. The more you do this, the more resilient you are to setbacks that will happen on the day of your boards part 3. Since you cannot control much in terms of patients, environment, or equipment, the script and your skills are one thing you can control in terms of how well you know it inside out.
3. Psychology
It's understandable to feel utterly defeated when you discover that you failed part 3. After all, we all know these skills because we've all passed multiple proficiencies and done these skills countless times on real patients. Once you get over the sadness and self-pity, realize that this is just a hoop we all have to jump through in order to become qualified eye doctors. You wouldn't want a dentist working on your teeth if he never passed his boards exams, right? As much as it may feel like we failed because of bad luck, you have to let go of that mindset and focus on doing 100% of the things you can in order to maximize your chances at passing.
Mentally, it is important to know that you have everything within you to pass this exam. It will not come without hard work. Once you've put in all that work, BELIEVE IN YOURSELF. You will know when you have done everything you can to prepare. Trust all your years of hard work and perseverance. You are so close to the finish line, and you will emerge on the other side an amazing doctor after recovering from these obstacles.
I personally had one of my patients in my fourth-year vision therapy clinic hypnotize me, as crazy as that sounds. I was willing to try anything to overcome my self-doubt after failing the first time. She painted me a beautiful picture of my future as an incredible eye doctor, after I passed my boards and achieved all my goals. Sometimes when you have to bridge the gap between lack of experience and confidence, you do have to "fake it until you make it". You have to believe that you can do it, and act like it. Do whatever it takes for you to gain that confidence in yourself. Write a list of your accomplishments, remind yourself that you've made it this far, and know that you will still be a great eye doctor even if you failed a boards exam.
Some people can get lucky and pass the first go, without doing all of these precise steps. If this is your first time, are you willing to risk precious time (months of practicing and 2 months to find out your result) and over $1.5k on luck? Do everything you can in your power, and there will be a very slim chance that you will fail. I thought I prepared as hard as I could the first time, but I was wrong. You can never over-prepare for this exam, and the more you know your script inside and out, the less prone you are to being affected by any little thing that goes wrong. And there will be things that go wrong, so help yourself the best you can to prepare for it.