A 4-year-old male domestic chinchilla presented with cloudy lenses for 1 month. Ophthalmic examination revealed that there was a mature cataract oculus dexter (OD) and a hypermature cataract oculus sinister (OS). Menace response was negative oculus uterque (OU). Dazzle reflex responses of OS and OD were positive and negative, respectively. Pupillary light reflex was positive OU. The conjunctiva, cornea, anterior chamber, and iris were normal OU using a slit lamp biomicroscope (Kowa SL-17 Portable Slit Lamp Biomicroscope; Kowa Co. Ltd.; Tokyo, Japan). Intraocular pressures (IOPs) were measured OU using a rebound tonometer (Icare®TonoVet; Icare Finland Oy; Helsinki, Finland) and were normal values (8 mmHg OD; 7 mmHg OS). Fundoscopy could not be performed due to the cloudy lenses OU. In this case, the definitive diagnosis was mature cataract OD and hypermature cataract OS (). The treatment was performed using phacoemulsification without intraocular lens implantation OS. However, OD was not advised to treat with surgery due to the dazzle reflex OD being negative. Application of 0.5% ketorolac tromethamine (Acular®; Allergan Pharmaceuticals Ireland; Westport, Ireland) was prescribed to control lens-induced uveitis (LIU) OU every 24 hours. The results of the pre-operative physical examination were normal. The hematology and blood chemistry were evaluated and were within normal limits. B-scan ocular ultrasonography (Logiq E9; GE Healthcare; WI, USA) with topical 0.5% tetracaine hydrochloride (Alcon®; Alcon-Couvreur; Puurs, Belgium) was evaluated with no evidence of retinal detachment OU. Pre-operative medications were prescribed with topical 1% prednisolone acetate and 0.3% ofloxacin (ExopredTM; Piramal Pharma Limited; Madhya Pradesh, India) OS every 8 hours for 3 days before surgery. Before surgery, topical 1% tropicamide (Mydriacyl®; Alcon-Couvreur; Puurs, Belgium) was applied every 15 minutes for 30 minutes to mydriasis. The chinchilla was anesthetized with 8% sevoflurane (Sevo; Singapore Pharmawealth Lifesciences, Inc.; Laguna, the Philippines) in the induction chamber and maintained with 2% sevoflurane with a face mask. Electroretinography (ERG) using a (handheld multispecies electroretinograph model 2000; Ocuscience LLC; MO, USA) based on the QuickRetCheck protocol was performed immediately before surgery. The ERG values are presented as a flat graph OD and low amplitude OS. With high light-intensity (10 cd.s/m2) stimulation, the b-wave amplitude was 3.8 µv and the implicit time was 1.3 ms OS. Based on the result of the ophthalmic reflex, ERG values, and the anatomy of the eye size, phacoemulsification without IOL implantation was performed OS. The surgical area was sterilized with 1:50 diluted povidone-iodine solution before starting surgery OS (). Then, 5 mg/kg marbofloxacin (Marbocyl®; Vetoquinol; Lure, France) and 4.4 mg/kg carprofen (Rimadyl®; Inovat Industria Farmaceutica Ltda; Sao Paulo, Brazil) were administered subcutaneously. The position during surgery of this chinchilla was lateral recumbency because the globe of the chinchilla was lateral. The corneal incision was created at the 11 o’clock position of the clear cornea near the limbus with a 2.8 mm slit-angled knife (Mani®Ophthalmic Knife; Mani, Inc.; Tochigi, Japan), as shown in. A viscoelastic substance containing 2% sodium hyaluronate (Viscovet; AJL Ophthalmic, S.A.; Álava, Spain) was applied to the anterior chamber to maintain the anterior chamber and protect the corneal endothelium during surgery (). The 25 gauge needle was inserted in the anterior chamber to scrape a tear for the initial opening in the anterior lens capsule. Additionally, a capsulorhexis was performed using the Utrata capsulorhexia forceps together with the intraocular scissors (). Furthermore, a one-handed phacoemulsification (Centurian; Alcon® Surgical; TX, USA) technique using balanced torsional phaco tip was performed (). During the phacoemulsification period, iris prolapse was found at the incision site due to the anterior chamber being shallow and the iris position was anterior to the cornea. The cataract is quite hard to remove. Thus, the settings of the phacoemulsification were an average of 48.2% longitudinal power with an average 58% torsional amplitude of phaco power. The torsional mode with a rotational movement was performed to remove lens materials and the U/S total time was 2.56 minutes. After the phacoemulsification, the posterior lens capsule was cleaned with the irrigation/aspiration mode. The balanced salt solution (BSSTM, Alcon Laboratories, Inc., TX, USA) was added with 2 ml of 1 mg/ml epinephrine bitartrate (Adrenaline, Atlantic Laboratories Corporation Ltd., Samut Prakan, Thailand) and 0.1 ml (25,000 I.U./5 ml) of heparin sodium (Nuparin, Troikaa Pharmaceuticals Ltd., Gujarat, India) per 500 ml of fluid was used to irrigation during and after phacoemulsification to prevent fibrin formation in the anterior chamber. Then, a remaining viscoelastic substance containing sodium hyaluronate was removed from the anterior chamber and capsular bag. The procedure was terminated after the corneal incisions had been sutured with a simple, interrupted pattern using 9/0 polyglycolic acid suture material (PGA; FSSB Chirurgische Nadeln GMBH; Jestetten, Germany), and were reinflated with the balanced salt solution (). Postoperative medications were prescribed orally with 5 mg/kg marbofloxacin every 24 hours (Marbocyl®; Vetoquinol; Lure, France) and 0.3 mg/kg meloxicam every 24 hours (Melox®; Siam Bheasach Co., Ltd.; Bangkok, Thailand) for 1 week. In the postoperative period, topical 1% prednisolone acetate in combination with 0.3% ofloxacin every 8 hours and 3 mg/ml sodium hyaluronate (Hialid®0.3; Santen Pharmaceutical Co., Ltd.; Ishikawa, Japan) every 8 hours were administered OS for 4 weeks. Ketorolac tromethamine 0.5% was used every 24 hours OD continuously to control LIU. An Elizabethan collar was applied around the neck to protect the eyes from rubbing by the patient for 1 week. Two days after surgery, the chinchilla could comfortably open both eyes. However, mild corneal edema and conjunctivitis were evident in OS. The IOPs OD and OS were 7 and 8 mmHg, respectively. Two weeks postoperatively, the chinchilla was more alert when compared to before surgery and could jump on and jump off the ledge in his house. Ophthalmic examination revealed the corneal wound had been sealed, and lens capsule opacity and the iris trap at the surgical site were presented OS (). The clear cornea and cataract were presented OD. In the ophthalmic examination room, when the veterinarian approached closely OS, the chinchilla displayed a held-up head, open eyes, erect ears, and immobile positioned forward indicating alertness or fear, whereas the chinchilla was ignored when the veterinarian doing the same OD. At 4 weeks after surgery, the chinchilla was more alert when compared to before surgery and could jump on and jump off the ledge in the new environments in his house. At 6 weeks postoperatively, the examination of OS presented posterior capsular opacity (). The IOPs were within the normal limit OU (range: 5–9 mmHg OU) during follow-up times. The chinchilla maintained alertness and his vision improved by this chinchilla could jump on and jump off the ledge without bumping any objects in his house. It was noticed that the chinchilla could able jump on and jump off the ledge and jump past the objects without bumping new objects in his areas and his vision was adequate for life throughout 18 months postoperatively.