Draco lost his sight when he was twelve years old, due to a curse on the Malfoy family

"The eyes of every Malfoy, upon reaching twelve years, shall be useless, for they shall not see, and their curse shall only be broken when they learn to love... and be loved."

His life became miserable; he didn't feel enough

One day, Rosalinda approached and complimented,

"What a preciousness I find in your gaze,"

he said, unaware of the boy's condition.

The boy didn't react offended but rather, saddened