Conn. Gen. Stat. § 31-349: Compensation for second disability.

The fact that an employee has suffered a previous disability, shall not preclude him from compensation for a second injury, nor preclude compensation for death resulting from the second injury. If an employee having a previous disability incurs a second disability from a second injury resulting in a permanent disability caused by both the previous disability and the second injury which is materially and substantially greater than the disability that would have resulted from the second injury alone, he shall receive compensation for (1) the entire amount of disability, including total disability, less any compensation payable or paid with respect to the previous disability, and (2) necessary medical care, as provided in this chapter, notwithstanding the fact that part of the disability was due to a previous disability. For purposes of this section, “compensation payable or paid with respect to the previous disability” includes compensation payable or paid pursuant to the provisions of this chapter, as well as any other compensation payable or paid in connection with the previous disability, regardless of the source of such compensation.