Rod of Tremorsense

Describe an invention in your world that helps people with disabilities. 
An elven man walks along the bustling city street, using a long staff as a walking stick. On one end is a rough piece of leather, textured and scraping the ground even with each step, and on the other, a green gem is wrapped in several tendrils, pulsing with light slightly. As the man reaches a step, he stops, the staff held in front of him in the air. He gently drops it down, letting it thud slightly against the ground. His feet adjust, and with a new knowledge of the next several steps in front of him, the man starts heading down the stairs towards the small park ahead.
The Rod of Tremorsense is a tool that is made by clerical enchanters, as a tool to give aid to people in Sitenautem that have lost their sight for various reasons. The rod is laced with a specific magic that allows it to send out vibrations through the ground, and for them to return to the person after bouncing back from objects around them. This allows for the user to build a general sense of the area that is around them, providing them ease in day-to-day life, especially in traversing the world outside of their home.

Access & Availability

This object is widely available through any sort of healer, cleric, or temple dedicated to such. Any person who is in need of one can go to a person or place like this, and ask, and will be granted one that they can use. Every healer is taught how to make one of these eventually, and before any healer can go off on their own away from a teacher or temple, they must learn this skill (among a few other similar ones) in order to provide it to anybody who requires it. While some people may go off on their own as healers without ever learning this, they always know the way to someone who does.

Complexity

Surprisingly, the magic that is needed for this is relatively simple to learn, compared to many other spells and effects that can be used. In general, the only components needed are for the spell to be placed on it, and a rod created with a magical gem embedded in it somehow.