guys, for the past few weeks, I didn’t wear glasses at all because I was looking for what lenses I should wear. but when I checked astigmatism, my axis moved from 180 (a few weeks ago) to 5 (now) even though I haven’t been wearing any lenses for the past few weeks. is that normal? can axis astigmatism change without the use of lenses?
It has happened to me - twice. Cylinder correction can trap the eye in a certain degree and axis of astigmatism. If you think you still need cylinder in your lenses, make sure you check your axis a few times, at different times of the day, before committing yourself to any axis or degree of cylinder. If you can do without it, this will allow your astigmatism to fluctuate naturally during the course of the day. You could also try a spherical equivalent (SE) but check out the posts on the website and the forum first, so that you know what you are doing.
but spherical equivalent can only be used to reduce cyl, am I right? if we use it to reduce sph then we won’t get blur
SE is not ideal as it gives too little blur challenge to the stronger axis and too much to the weaker one. But it can prevent you from keeping your astigmatism axis ‘trapped’ by a cylinder correction. It is definitely not recommended for high cylinder.
Thanks for your explanation
is it okay if I stray just 1 degree in using a cyl lens? it is difficult to determine the right degree for astigmatism
For ex: my true Axis : 4°, but I wear 5°
I think a range of up to 10 degrees is considered acceptable, and 1 or 2 degrees is certainly no problem. My changes in axis were much larger than that, and made my lenses with cylinder correction unusable.
You only changed by 5 degrees, 180 is the same as 0, and most doctors don’t even bother moving by such small amounts.