You are eligible for this exemption if you are unable to engage in gainful work because of a physical or mental disability or you are 55 years old and blind and are unable to engage in your previous work because of the blindness. To qualify, you must meet the Social Security definition for disabled. You qualify if you receive disability benefits under the Federal Old Age, Survivors and Disability Insurance Program administered by the Social Security Administration. Disability benefits from any other program do not automatically qualify you. To prove your eligibility, you may need to provide the appraisal district with information on disability ratings from the civil service, retirement programs, or from insurance documents, military records, or a doctor's statement.