Design considerations for vision and motion

This is a research based session, 

Visual Depth Cues

  • Make sure your content provides depth triggers so the brain can perceive the data correctly
  • Visual system interrupts what is perceived, Making things agree is important for vision comfort, around line of sight.  The Depth cues help the brain handle this.. if it is not right you can cause users with eye fatigue or double vision.
  • You can use size, gentle motion, color, blur, light, shadow, backgrounds, and occlusion 
  • Conflicting clues can also provide issues to your user. Repeating patterns can cause eyes to mis-focus across multiple items causing issues.

Content Parameters

  • Make sure to place reading, farther than arms length, and let users to adjust for comfort.
  • Direct interaction or quick goes can be placed closer.
  • Use blur and transparency to help users focus their eyes.
  • Use high contrast for reading, and keep it centered to keep the user from having to move head back and forth.
  • Slow transitions between dark and light scenes 

Eye effort

  • Minimize eye effort demanded from your users, it is most comfortable to look down, or left and right. So use that for content to reduce eye strain.
  • Upward and diagonal movement is the most effort.
  • Longterm should be in the center and slightly down of the field of view.
  • Allow for natural break points in your experience to allow for eye rest.

Motion of virtual objects

  • Inner ear is used, along with your eyes, to address motion.  If these two disagree you can get dizzy or sick to your stomach.
  • If things move at the user, you should make your objects semi-transparent to reduce discomfort    

Head-locked content

  • When possible use this, since they will not come at the user. You can use a lazy follow, which moves content in position slowly over time, reducing issues.

Motion in windows

  • Pay attention of the motion of content within a window, make sure that horizon stays align with the same as the real horizon.  Focus of expansion should be slow and predictable (and within the field of view), reduce pure rotational changes.  You can just use a quick fade with shift during it.  Using smaller objects and plain textures are better.

Oscillating motion