This disclosure features bis(diazirine) derivatives of the formulae (I) (l-a) or (l-b) that generate cross-linking in the cornea in response to exposure to an electromagnetic irradiation (e.g. UV-light). The compounds are useful, e.g. for treating a subject (e.g. a human) having a disease, disorder or condition in which abnormal shaping of the cornea (e.g. thinning of the cornea, e.g. bilateral thinning of the cornea, e.g. bilateral thinning of the central, paracentral, or peripheral cornea, or steepening (e.g., bulging) of the cornea) contributes to the pathology and/or symptoms, and/or progression of the disease, disorder or condition. Examples of such diseases, disorders or conditions include: (i) corneal ectatic disorders； (ii) vision conditions； and (iii) diseases, disorders, or conditions that are sequela or comorbid with any of the foregoing or any disclosed herein. More particular examples of such diseases, disorders or conditions include keratoconus, keratoglobus, pellucid marginal degeneration, corneal ectasia (e.g. postoperative ectasia, e.g. post-LASIK ectasia), Terrien's marginal degeneration, myopia, hyperopia, astigmatism, irregular astigmatism and presbyopia. In some embodiments, the claimed methods can be performed in the absence of added or supplemental oxygen levels, which can be advantageous in some applications. Preferred exemplary compounds are e.g. bis(diazirine) amino acid derivatives, such as e.g. example 1:La présente invention concerne des dérivés de bis(diazirine) de formules (I) (l-a) ou (l-b) qui génèrent une photo-réticulation dans la cornée en réponse à une exposition à une irradiation électromagnétique (par exemple, une lumière UV). Les composés sont utiles, par exemple, pour traiter un sujet (par exemple, un être humain) qui présente une maladie, un trouble ou un état pathologique dans lequel une mise en forme anormale de la cornée (par exemple l'amincissement de la cornée, l'amincissement bilatéral de la cornée, l'amincissement bil
