DS on an eye prescription means your correction is spherical only — you have no astigmatism, so there's no cylinder (CYL) or axis value to record. It appears in the CYL column in place of a number, and it means the same thing as that column being left blank or filled with 0.00.
Why it's written out instead of just left blank
An empty box on a prescription is ambiguous — did the optometrist forget to fill it in, or is there genuinely nothing to enter? Writing "DS" removes that doubt: it's a deliberate note meaning the sphere power alone (the SPH value) is your full correction, with nothing further needed for astigmatism.
What this changes about the rest of your prescription
Not much, practically — a CYL value only ever appears alongside an AXIS value (the two always go together), so DS in the CYL column simply means you can skip the AXIS box too. Everything else on the form — SPH, ADD if you have one, and PD — is read the same way regardless.
This page explains the notation, not your eyes — it doesn't interpret what any value means for your vision. For what every other box on the form stands for, see how to read your full prescription, including SPH, ADD and PD and how to send it to us when you order.