Download the 5 files from this link:

1. ViewPointwritedemo20040713.m
2. ViewPointreaddemo20040713.m
3. ViewPointchar2double.m 
4. Matlabdatacapture.mat 
5. ViewPointdatacapture

ViewPointwritedemo20040713.m works on its own.  It shows how to properly use PsychSerial('Open') and PsychSerial('Write') to send commands from Matlab to ViewPoint.  It also has a lot of comments at the top from numerous emails and notes I have sent to others about this.

ViewPointreaddemo20040713.m uses ViewPointchar2double.m and Matlabdatacapture.mat to show how to use the PsychSerial('Read') command to extract eye data from the serial data coming from ViewPoint to Matlab.  Depending on how you set choice, it can either read live data or work on the saved data in the MAT-file.

ViewPointdatacapture is just an example of a ViewPoint data file.