Modular lens adapter system are provided for use with a hand held computer device having a camera for mobile ophthalmoscopy. The modular lens adapter systems include an anterior adapter and a posterior adapter configured to removably engage with a hand held computer device. The anterior adapter can include a variable intensity light source, a clamp, and a movable macro lens. The posterior adapter can include a hand held computer device mount, a lens mount, and a telescoping arm with a first end and a second end with the first end configured to removably engage with the mount and the second end configured to contact the lens mount. Methods are also provided for using the systems to obtain an image of an anterior portion of the patient's eye and a posterior portion of the patient's eye.