Which formula is sometimes used for bilateral vision impairment when calculating disability?

• A. Reduction of vision plus 1/2 the difference between disabilities 2.4 and 2.3
• B. Best corrected vision only
• C. Uncorrected vision only
• D. Whichever eye rates highest

Answer: (A)

When evaluating bilateral vision impairment, you combine both eyes’ losses rather than rely on a single eye. The method used adds the overall reduction of vision to half of the difference between the two eye disability values. This balances the impact of unequal impairment between eyes: if the eyes are similarly impaired, the difference is small so the adjustment is minor; if one eye is notably worse, only half of that imbalance is added, avoiding double-counting the more affected eye while still recognizing the contribution of the other eye.

The two eye disability values (often labeled as 2.4 and 2.3 in the schedule) represent each eye’s impairment, and taking their difference captures how uneven the impairment is. Halving that difference then adds a modest adjustment to the base reduction of vision to produce a single bilateral rating.

Other options either ignore the bilateral nature (best corrected vision only or uncorrected vision only) or oversimplify by just taking the worse eye, which can misrepresent the true functional loss when both eyes contribute to vision.