I really like this concept! Plus being born with a physical disability being regarded as a halmark of heroic lineage feels unique.
I only wish the author would dial up the MC's other senses. For example unsighted people usually have a better sense of touch, taste/smell, vibration and hearing. He'd know the difference between an apple and an unknown piece of fruit from the scent alone, nevermind the obvious difference in flesh rigidity.
The unsighted also can create maps of memory in areas they frequently travel, augmented by the sound bouncing off nearby surfaces.
I can imagine this is difficult to illustrate but one technique from a manga I've read was when an unsighted maid was pouring tea for a guest, she did so while pressing one fingertip along the inner rim of the teacup. When the tip of her finger touched the tea (ouch, hot!), she knew it was time to stop pouring.
Things like this, tracing one's fingers along the wainscoting panels on a wall while walking, and feeling the doorjamb first and then working towards the latch are great ways to illustrate that your character has poor or no vision and putting your readership into the shoes of the character