A hydrogel forming composition comprising: a) 5 - 70 wt.-% of at least one water-soluble (meth)acrylic compound, b) At least one free radical initiator, c) At least one catalyst for free radical formation, and d) 20 - 75 wt.-% of water, all proportions being based on the total weight of the hydrogel forming composition, wherein the at least one catalyst for free radical formation is an amine compound of formula (I) wherein R 1 to R 5 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 0; or R 1 to R 8 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 1 ; or R 1 , R 2 , R 7 , and R 8 together form a 5- or 6-membered ring structure with the two nitrogen atoms, R 3 to R 6 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 1, and wherein the at least one water-soluble (meth)acrylic compound is selected from the group consisting of hydroxyethylmethacrylate (HEMA), hydroxypropylmethacrylate (HPMA), methoxy polyethylene glycol methacrylate (MPEG-MA), polyethylene glycol dimethacrylate (PEG-DMA), maleic acid, itaconic acid, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, magnesium acrylate, potassium salt of 3-sulfopropylacrylat, 2-acrylamido-2-methylpropane sulfonic acid, and sodium salt of 2-acrylamido-2-methylpropane sulfonic acid. a) 5 - 70 wt.-% of at least one water-soluble (meth)acrylic compound, b) At least one free radical initiator, c) At least one catalyst for free radical formation, and d) 20 - 75 wt.-% of water, all proportions being based on the total weight of the hydrogel forming composition, wherein the at least one catalyst for free radical formation is an amine compound of formula (I) wherein R 1 to R 5 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 0; or R 1 to R 8 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 1 ; or R 1 , R 2 , R 7 , and R 8 together form a 5- or 6-membered ring structure with the two nitrogen atoms, R 3 to R 6 represent independently from each other linear or branched alkyl groups having 1 to 6 carbon atoms and optionally having one or more oxygen atoms, and n has a value of 1, and wherein the at least one water-soluble (meth)acrylic compound is selected from the group consisting of hydroxyethylmethacrylate (HEMA), hydroxypropylmethacrylate (HPMA), methoxy polyethylene glycol methacrylate (MPEG-MA), polyethylene glycol dimethacrylate (PEG-DMA), maleic acid, itaconic acid, sodium acrylate, sodium methacrylate, potassium acrylate, potassium methacrylate, magnesium acrylate, potassium salt of 3-sulfopropylacrylat, 2-acrylamido-2-methylpropane sulfonic acid, and sodium salt of 2-acrylamido-2-methylpropane sulfonic acid. <EOS>