Ocular centration of visual axis and evaluation of retinal function

1. A method to assess recovery of a compromised retinal area in a patient, the method comprising

moving an external light source at a predetermined speed laterally across a fovea of a patient's eye, the external light source moving across a centration image causing the patient to detect a continuous line afterimage on said centration image that is projected or marked on a device in the patient's visual pathway, the device comprising at least two concentric rings upon which the centration image is projected,

immediately removing the external light source upon the patient indicating detection of the continuous line on the centration image,

determining the time interval between the patient detecting the continuous line afterimage on the device, the device comprising at least two concentric rings upon which the centration image is projected or marked and the patient detecting a discontinuous line on the centration image that is projected or marked, and

comparing the patient's time interval to a known time interval to assess the patient's extent of recovery, a longer time interval indicating a compromised retinal area in the patient.

2. The method of claim 1 wherein the patient's time interval is compared to the time interval in a patient with an uncompromised retina to assess recovery of the compromised retina.

3. The method of claim 1 wherein the patient's time interval is compared to a previous time interval measured in the patient under substantially the same conditions to assess extent of recovery of the compromised retina.

4. The method of claim 1 wherein the area is specifically located by a centration method.

5. The method of claim 1 further comprising having the patient indicate seeing the afterimage from the light source.

6. The method of claim 5 wherein the presence of at least two afterimages indicates at least two compromised areas of the retina.