- Apply the +1.00Ds blur test. If the VA is reduced to 6/12 or so leave the +1.00DS in. If not, adjust the fogging lens until it does.
- Refract the left eye with the right eye fogged, i.e. binocularly.
- Apply the +1.00DS blur test to the left eye.
- Check the final sphere balance of the right eye binocularly with the +1.00DS still in place before the left eye.
If you need to add a substantial amount of plus because your retinoscopy result was some way out, it is worth checking the fogged eye periodically to ensure that it is still fogged.
Sometimes the addition of plus to the eye being refracted will cause both eyes to relax accommodation