Jake says you need to reduce cyl for differentials. I first thought why? Your eye at that axis will always be that much more myopic, even near unless you have 20/20 and as you go near the stronger part of the eye bends to decrease the difference between that axis and overall sphere’s myopia. But e.g if you have -3.75 sph and -1.25 cyl. you need +1.75 under correction for 60 cm computer screen. I thought maybe you’re not fully at the edge of blur because you need to be 61cm and any more your cm you are -1.5 i thought maybe if youre not fully at edge of blur the difference decreases since stronger part bends more. Is that why you need less astig for near if so in that case just -0.25 reduction in astig or -0.5 for near should be more than enough why did jake say in one video if you have -200 cyl maybe you need -1.00 for near. unless its a case by case scenario i need clarifrication
Astigmatism is uneveness in clarity within the eye and that will always be at the same axis. But the difference between overall lens correction and the correction in the cylinder can reduce. Your eye won’t be much more myopic at that axis always, it can be improved and just be slightly more myopic at that axis.
For close up work you need less corrections overall, and often you will find that less is true for cyl correction, too.
Typically -0.25D or -0.5D cyl can be dropped easily without causing any additional blur or double vision close up. Cyl around -1.00D may be dropped totally or done in 2 steps of -0.5D’s. Above -1.00D cyl typically your brain is already used to the significant uneven correction within the eye and it is recommended to take about -0.5D steps.
It all depends on how strong your cyl correction is and how long you wore it => how much are you used to being corrected for cyl.
Hope it helps