Contact lenses used in laser
Lens type Field of 
Laser spot 
Spot size magnification
(Spot size set at 200mm)
Corneal image 
Volk Quadraspheric 1300 1.92 400 19mm
Mainster wide field 1250 1.47 294 30mm
Volk transequator 120-1250 1.43 286 28mm
Volk area centralis 80-900 1.01 200 38mm
Goldmann 3 mirror 360 1.08 216 -7mm

1. The smaller the image magnification, the larger the size of the burn for example Volk quadraspheric gives 
    half the image magnification of Volk area centralis but produces a laser burn spot of twice the size.

2. The larger the burn spot size, the lower the power density. The power of the laser may need to increase.

3. The larger the burn spot size, the lower the number of burn needed to cover a specified area.

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