I've been using an Elecom EX-G left-handed wireless trackball (thumb operated) for ages: https://www.amazon.co.uk/ELECOM-Left-handed-Wireless-function-M-XT4DRBK

I've been using an Elecom EX-G left-handed wireless trackball (thumb operated) for ages: https://www.amazon.co.uk/ELECOM-Left-handed-Wireless-function-M-XT4DRBK-Black/dp/B016QCPRBM https://www.amazon.co.uk/ELECOM-Left-handed-Wireless-functio... I'm naturally right-handed, but learnt to use a mouse/trackball with my left hand ages ago when I figured out the twisting/ergonomic issues with a right-handed mouse and a keyboard with a numeric keypad. I was previously prone to hurting my right-shoulder blade (pulled muscle?) as there's a constant twist compared to the mid-line of the keyboard.