Van herick&;s angle grade 3 of anterior chamber denotes

Van herick&;s method:*To evaluate the chamber depth of the right eye, turn the lamp so that the light is coming at the temporal limbus at an angle of 60 degrees. Change the slit to its most narrow setting, and direct the beam onto the cornea, just barely to the right of the limbus. *You should see three things: the beam of light sharply focused on the cornea in a thin slit, the light falling on the iris(unfocused), and a dark interval in between.* The dark interval is the area of interest, as it represents the chamber's depth. *If this shadow is one-quaer to one-half the width of the illuminated corneal section, the angle is open. If the dark section is less than one-quaer the width of the corneal beam, the chamber is narrow. If there is no dark interval (ie, the corneal and iris beams meet), the angle is extremely narrow or closed. The chamber is graded from 1 to 4 or labeled as closed, open, shallow, or moderate.FeaturesGradeClosed angle0Angle extremely narrow, probable closure1+Angle moderately narrow, possible closure2+Angle moderately open, closure not possible3+Angle wide open, closure not possible4+Ref: The slit lamp primer; 2nd edition; Pg. 41