At present no cure exists for this condition, and as it affects only a very small number of people it hasn't generally been the object of a great deal of research. However, the condition is now better understood than it used to be and there are measures which can be taken to help sufferers manage their condition better.
A major problem with achromotopsia is extreme light sensitivity. People with this condition often have to avoid bright light as they get dazzled by it. There are now red lenses which can be worn to reduce sensitivity. With incomplete achromotopsia, where the person has some awareness of colour, lenses and special glasses can sometimes improve this awareness so the person can, for example, distinguish between different colour traffic signals. People can also learn or be helped to manage their condition by working in an environment with reduced glare, and other practical measures.
You can learn more about the treatment of achromotopsia here.