Would like to add to this post on "vestibular exercises". They most certainly help and David's one where you're on the cushion in a corner is very good. This similates "soft surfaces" like grass, yoga mats, sand, carpets, etc.
Try his exercises and add my favorite one....with legs apart extend arm out in front of you holding thumb up. Focus on thumb and "slide" it slowly right and left while keeping your balance. Do this for up to one minute. The movement isn't great, just slide it far enough so the eyes end up in the corners of your sockets then slide the other way. With time you will be able to move your arm/hand quicker.
When you've got this one down, try a more challenging one. With feet hip width place left or right foot ahead of the other similating a "walking step". Then extend arm with thumb up and begin the slow slide left and right all the while staring at your thumb. You will begin to see the background moving rapidly almost a blurr.
These exercises (staring at thumb) similate being able to focus on one object while moving your head and at the same time the background moving faster without falling off balance. This happens to us outside, malls, large open areas in stores, etc. Really helps get rid of the "oops" moments when we turn our heads quickly on soft surfaces or while walking. The key is to start ever so slowly increasing speed when you've got the "slow mo" down pat.
Add another one when you're ready. Try staring at your thumb while moving it on a diagonal plane. Raise right arm up and to the right, stare at thumb while you lower arm across chest until you see your left shoulder. Bring thumb back across chest and up to the right (head movement is up to the right, down to the left). Do this over and over increasing speed, then switch to the left. Switch up your foot stance too. This similates looking up at trees and down at the ground quickly.
Very annoying to have to do these, but very effective! Good luck everyone hope this helps. And a word of caution with yoga (I'm an instructor), be mindful of turning your head with spinal twisting asanas. You can cause trigeminal nerve to "fire" creating a headache. I stopped turning my head while spinal twisting and this helped. I used to create a headache sometimes where they would start in the incision occiput area. Be mindful always of tension with facial muscles, tongue, neck, shoulder and muscles used to control scapulas. Always relax them while in the posture, if you find you hold tension in these areas you need to back off the posture (don't go so deep), use blocks, blankets to support you until you can perform them without creating tension in these areas.
Have a great day everyone!