<prompt> Earliest field defect in primary open angle glaucoma:Reidels scotomaScotoma in Bjerrumns fieldArcuate scotomaNasal spur  <response>: Ans. is b i.e. Scotoma in Bjerrums field Visual field defects in Glaucoma:Baring of blind spotScotoma in Bjerrums fieldArcuate scotomaSeidels scotomaRing or double arcuate scotoma.Roennes central nasal step.Advanced field defect:At the last only a small island of central vision tubular vision and an accompanying temporal island are left.The temporal island is usually extinguished before the central island although occasionally this sequence is reversed. 