Which Windows OS are you using?
See if any of the following resolves your issue:
1) If Windows 7, https://support.microsoft.com/en-us/help/2396756/applications-using-bitmap-font-gets-effected-with-rendering-issues-if
2) Disable display scaling for MATLAB
- Right click on 'matlab.exe' icon and select "Properties".
- On the "Compatibility" tab, put a check mark on "Disable display scaling on high DPI settings".|