Please see fro reference IRS publication 463 page 36 -
Impairment-Related Work Expenses of Disabled Employees
If you are an employee with a physical or mental disability, your impairment-related work expenses are not subject to the 2%-of-adjusted-gross-income limit that applies to most other employee business expenses. After you complete Form 2106 or 2106-EZ, enter your impairment-related work expenses from Form 2106, line 10, or Form 2106-EZ, line 6, on Schedule A (Form 1040), line 28, and identify the type and amount of this expense on the dot-ted line next to line 28. Enter your employee business expenses that are unrelated to your disability from Form 2106, line 10, or Form 2106-EZ, line 6, on Schedule A (Form 1040), line 21.
Impairment-related work expenses are your allowable expenses for attendant care at your workplace and other expenses in connection with your workplace that are necessary for you to be able to work.
You are disabled if you have:
A physical or mental disability (for example, blindness or deafness) that function-ally limits your being employed, or
A physical or mental impairment (for example, a sight or hearing impairment) that substantially limits one or more of your major life activities, such as performing manual tasks, walking, speaking, breathing, learning, or working.
You can deduct impairment-related expenses as business expenses if they are:
Necessary for you to do your work satisfactorily,
For goods and services not required or used, other than incidentally, in your personal activities, and
Not specifically covered under other income tax laws
Example 1. You are blind. You must use a reader to do your work. You use the reader both during your regular working hours at your place of work and outside your regular working hours away from your place of work. The reader's services are only for your work. You can deduct your expenses for the reader as business expenses.
Example 2. You are deaf. You must use a sign language interpreter during meetings while you are at work. The interpreter's services are used only for your work. You can deduct your expenses for the interpreter as business expenses.