Invalidity pension is a social insurance payment payable to people who are permanently incapable of work and who satisfy the PRSI contribution conditions. Blind person's pension is a means tested payment payable to blind or partially sighted people who are so impaired that they cannot perform work for which eyesight is essential or cannot continue in their ordinary occupation. As such, both pensions cater for an inability to earn an income due to an incapacity or disability. A principle which applies in social security schemes generally is that, while a person may satisfy the conditions for more than one payment, only one payment is made at any one time. There are no plans for concurrent payment of invalidity and blind pension.