snellen test การใช้

• However, with star-spotting, you are violating the standard illumination conditions of the Snellen test just a teensy bit, so I doubt that this result is meaningful.
• At 20 / 20, each letter subtends 5 minutes of arc, so each grid cell subtends 1 minute . " Recklessly assume " that resolving two stars is the same as perceiving a single black cell between two single white cells ( which of course is not what happens in a real Snellen test ).