Provided is a method for improving day photopic vision and/or cone-derived visual field and visual function in a subject suffering from a retinal disease or trauma including administering to the subject a pharmaceutically effective amount of crude Dunaliella powder. Also provided is a method for improving night vision and/or rod derived visual field in a subject suffering from a retinal disease including administering to the subject a pharmaceutically effective amount of crude Dunaliella powder. A pharmaceutical composition for improving day vision and/or visual field in a subject suffering from a retinal disease including crude Dunaliella powder is also provided.