This thread is a continuation of one started by user haydon.sheppard here:https://forums.oculusvr.com/community/discussion/comment/613239#Comment_613239
Not everyone has the best visual experience when first strapping on the Oculus Go. Some users are reporting an inability to get a clear, focused image on the Go display. Barring some fault in a specific Go's assembly most if not all of the focus issues boil down to one or a combination of four things.
1) The Go headset is incorrectly positioned in front of the users eyes.
2) The media content that is being viewed is out of focus or low resolution and thus appears blurry.
3) The user's eyes require corrective lenses and they are not being worn.
4) The corrective lens inserts or glasses worn by the user are unsuited to the optical working distance of the Go.
This discussion will focus on item 4.
The Go can be worn comfortably with glasses but depending upon an individual's prescription a particular set of glasses may not work well with the Go's optics. The case in point that has been under discussion in the thread mentioned above is where the prescription being worn contains a progressive or no-line bifocal configuration and the user's eyes also have fixed focus lens implants as a result of cataract surgery. The particular lenses being worn allow a mixture of focal distances depending upon the vertical angle of view: Straight ahead - distance focus, angled down - near focus. Along with other factors related to the manufacture of progressive optics this causes a significant narrowing of the visual field that can be seen in focus. This means that the eyes can't be rotated to see other parts of the scene. Rather the head must be rotated to see other parts of the scene in focus, for example when reading across the page in the browser.
The solution to this problem is to get single focus glasses. However, for for optimum performance with the Go they should be prescribed for the Go's optical working distance. That is the apparent distance that the Go's optics simulate when when you look through them. For a young person that requires corrective glasses, with natural lenses in their eyes, the distance vision correction prescribed by the eye doctor is sufficient because their eyes can accommodate to the Go's optical working distance. For older users such as myself and particularly because I have fixed focus lens implants, a prescription must be calculated specifically for the Go's optical working distance.
My quest for the right prescription started with my eye doctor. He said that he would have to know more about the Go's optical working distance to write a prescription. I then went to Frames Direct, Oculus' provider of choice for lens inserts. They said they didn't have that information, they worked only with the distance vision prescription and referred me to Oculus support. At first Oculus support referred me to my eye doctor and Frames Direct but with additional (repeated) explanation they are looking deeper (higher) for information about the Go's optical working distance. Cybereality has suggested that the optical working distance is in the range from 1 to 1.5 meters. I'm hoping for something a bit more precise, say within plus or minus 1 inch.