The outcome of having a chalazion is usually excellent and there are few complications related to the condition. However, if the chalazion is large this can cause astigmatism. This is due to the pressure placed on the cornea by the eyelid. Astigmatism is when your cornea (the front part of your eye) has an irregular shape. Instead, of being its usual round shape it is oval shaped (like a rugby ball). This makes focusing difficult and causes vision to be blurred.
A chalazion puts pressure on the cornea forcing it to change its shape which causes the astigmatism.
This usually corrects itself as soon as the chalazion disappears.
