The Human Eye

The illustration above shows the appearance of a human eye under average lighting conditions. Notice that the iris occupies half the width of the visible eyeball and is partially covered at the top, and to a lessor degree at the bottom by the eyelids. Trim the decal to achieve this appearance. The only time you will want to see the entire iris is when your figure's expression is one of shock.

Choosing the Correct Size Iris for Your Figure

Complicated Overview

The human iris is about .55" (13-14mm) in diameter, but different sculptors sculp the eyeball differently, and at the smaller scales even the slightest variation can be troubling.

It makes no difference how open the eye is, the width does not change, so to determine the correct diameter of the iris for your particular figure, measure the width of the eyeball and divide that dimension by 2.

In other words, if the width of the sculpted eyeball is 4mm, the correct size of the iris should be 2mm.

The Simple Solution

To eliminate the tedious measuring and guess work, we have introduced individual sheets of irises for specific scales from 1/35 to 1/4 scale HERE. Choosing one of those will, in 99% of the cases, be correct.

If you cannot find what you need there, here is a list of iris diameters found on the following sheets. If you do not see the exact size you need, use the next larger size.
Bigger is better.

AR99001- .032" (.81mm), .038" (.96mm), .044" (1.12MM), .051" (1.3mm)
AR99002 - .060" (1.5mm), .063" (1.6mm), .070" (1.78mm), .075" (1.9mm)
AR99003 - .084" (2.1mm), .104" (2.6mm), .126" (3.2mm)
AR99003A - .052" (1.3mm), .061" (1.55mm), .079" (2.0mm), .097" (2.5mm), .127" (3.23mm), .150" (3.8mm)
AR99003B - .052" (1.3mm), .061" (1.55mm), .079" (2.0mm), .097" (2.5mm), .127" (3.23mm), .150" (3.8mm)
AR99064 - .072" (1.83mm), .084" (2.13mm), .120" (3.05mm)

John Ficchi has created a video tutorial on this topic: