Aurolab supplies Preservative Free Gonioscopic Solution. Aurolab is an ISO 9001:2000 accredited company. The Preservative Free Gonioscopic Solution, under the brand name ‘Goniogel’ is an isotonic, clear, colorless, viscoelastic solution. The Preservative Free Gonioscopic Solution contains methyl cellulose with a high molecular weight of greater than 80,000 daltons. No preservative added in this solution. The Preservative Free Gonioscopic Solution is used in bonding gonioscopic prisms to the eye.