Handbooks have summaries of commonly used information, including formulas, calculations and properties.
FINDING JOURNAL ARTICLES
Search the Compendex database to find research articles about robotic arms. You can also do a combined search with INSPEC, which includes computer and control papers. Click the "Get this at MIT" button to access full text of the articles.
Standards are extensively used in engineering to specify material measurements and specifications as well as safety standards and process guidelines. See a guide to what standards MIT Libraries have here.
Patents can show you how others have approached similar problems in creating devices or products. A guide to finding patents is here.
FINDING SPECS AND PARTS
Sensor books listed here
Use PubMed to find peer reviewed scholarly research articles on the technologies used by vision impaired people. Keywords to consider include self help technologies, blind, blindness, visually impaired, and vision impairment. Here's a search for you on assistive technologies for the vision impaired.
Comprehensive Physiology - primary reference in physiology. Physiology is the study of the way biological organs or systems work. Find information on the visual system and the eye.
BOOKS & ATLASES
Atlas of ocular anatomy. 2015
Check out the Technology section of Disability.gov for information about technology laws and regulations and types of assistive technologies available.
Check out the CDC's FastStats section on Disabilities and Functioning (Adults) for statistics regarding physical functioning difficulty and disability and health in the U.S., in general. Statistics on people with vision trouble and links to relevant reports.