美容性角膜接触镜的验配探讨

目的：为各种角膜白斑、虹膜异常的病人寻求医学美容及保留有用视力。方法Ｚ：对各种角膜白斑、虹膜异常的病人按有用视力和无用视力。分别进行有孔和无孔美容性角膜接触镜（俗称美容镜）的配戴。与健眼的虹膜色泽、瞳孔大小、舍适程度、配戴前后有用视力的评估。进一步统计分析探讨。结果：共收集４３０眼美容镜配戴者,有用视力的角膜旁中央白斑戴有孔美容镜４３眼,视力范围在眼前指数至０．６之间,戴镜前后的有用视力基本保持不变;无用视力的各种角膜白斑戴无孔美容镜３８７眼,能有效遮盖白斑,起到角膜美容的作用。结论：（１）各种角膜白斑的医学美容应首选配戴美容性隐形眼镜,既可逆性,又经济、安全、有效。（２）有孔美容镜既能有效遮盖角膜旁中央白斑,又能保留有用视力,两全其美。     

马来西亚一所私立大学使用视觉显示装置的学生非斜视双眼视觉异常

目的：评估马来西亚一所私立大学使用视觉显示装置(VDU)的学生非斜视双眼视觉异常(NSBVA)情况。

方法：对2019-01/2019-05期间每天使用3h及以上VDU的大学生进行横断面研究。使用一种简便的样本收集方法,所有受试者均通过初级视力检查且满足入选标准,对符合入选标准的学生进一步进行NSBVA评估。采用描述性分析排除NSBVA的百分比,采用Chi-square独立性检验,观察NSBVA与年龄、性别、VDU使用时间的相关性。

结果：研究共纳入140名学生,其中女88名(62.9%),男52名(37.1%)。受试者平均年龄为22.54±1.48a,平均VDU使用时间为5.76±2.49h。使用VDU学生的NSBVA百分比为40%。在VDU使用者中,调节异常和倾斜异常的发生率分别为17.86% 和22.14%。性别与NSBVA之间存在适度关联(P=0.010)。但是,年龄(P=0.334)和VDU使用时间(P=0.835)与NSBVA无显著相关。

结论：马来西亚一所私立大学的学生中,有40%的人使用VDU。在所有NSBVA中,VDU用户调节异常(15%)和会聚功能异常(10%)更为常见。     

Effect of the application of acetazolamide soaked contact lenses on intraocular pressure of rabbits

Topical application of acetazolamide has no known effect on intraocular pressure (IOP). We tried to detect the hypotensive effect on IOP of acetazolamide soaked onto soft contact lenses (CL). We applied CLs soaked in either 1%, 3%, or 5% acetazolamide solution onto one eye of 29 rabbits while the contralateral eye served as a control. There was an average 32% reduction of IOP amongst all acetazolamide applied eyes, and an average 19% reduction of IOP amongst all control eyes. Amongst the 1% acetazolamide-CL applied eyes there was a mean 37% reduction of IOP, amongst the 3% acetazolamide-CL applied eyes a mean 36% reduction, amongst the 5% acetazolamide-CL applied a mean 30% reduction, and a mean 19% reduction in control eyes. The longest period of IOP reduction followed the application of 1% acetazolamide-CLs, probably owing to improved drug corneal penetration at this concentration. Our results reveal that the application of acetazolamide soaked soft CLs has a significant hypotensive effect on IOP in both the applied and contralateral control eyes of rabbits.     

Congenital ptosis: results of surgical management

Purpose: To determine the visual and cosmetic outcome following the surgical correction of isolated congenital ptosis. Methods: A retrospective review of the outcome of isolated congenital ptosis corrected under the supervision of one surgeon at The Children's Hospital, Camperdown, between January 1983 and January 1993 was examined. Some 65 patients with 80 involved eyes were identified; 30 eyes underwent a levator resection procedure, 40 eyes underwent a brow suspension using donor stored fascia lata, and in 10 eyes a brow suspension was performed using mersilene mesh. Results: In 78 eyes of 63 patients, a good cosmetic result was achieved. In two patients (two eyes) a poor cosmetic result was achieved. These two patients refused further surgery following an undercorrection of their initial ptosis. The recurrence rates for the primary procedures were 16.7% for levator resection procedures, 35% for brow suspension procedures using donor fascia lata, and 30% for brow suspension surgery using mersilene mesh. Some 35.3% of eyes following mersilene slings required further surgery for granulomas and exposed mersilene mesh compared with 6% having similar complications with stored fascia lata. Nine patients (11.25%) had reduced visual acuity (one line or more on the Snellen chart or its equivalent with the other tests used) on the operated side. Only one patient was found to have significant astigmatism. Conclusions: An acceptable cosmetic result was achieved with one operation in 75.3% of cases. In 20.8% of cases a second operation was required and in 3.9% of cases three or more operations were required. This series supports the view that where possible, levator resection is the preferred form of surgery to correct congenital ptosis. When the levator function is inadequate, brow suspension is performed. The use of donor fascia lata resulted in a good cosmetic appearance with a low occurrence of surgical side effects. Amblyopia, when strictly defined, occurred in 11.25% of eyes despite early surgery for severe cases and intensive amblyopia therapy. Management requires repeated follow up for early detection and introduction of occlusion therapy or surgical ptosis correction.     

少年儿童眼外伤术后无晶体眼的接触镜矫正

目的探讨少年儿童单眼外伤术后无晶状体眼的接触镜(CL)矫正方法和临床效果.方法观察81名少年儿童眼外伤术后患者的眼部改变,并根据其屈光状态的变化、对侧眼的状态及其生活的实际需要,选择验配了软性接触镜(SCL)、托力克软性接触镜(TSCL)、透气性硬性接触镜(RGPCL)、加虹膜色彩的非透气性硬性接触镜(PMMA虹彩片)和软、硬组合型镜片系统(Piggyback CL),并比较视力矫正效果.结果与对侧健眼比较,外伤术后眼角膜曲率半径值显著改变,角膜散光度明显增加.52眼选用SCL和TSCL,矫正视力与框架眼镜比较无明显差异;22眼选用RGPCL,4眼选用PMMA虹彩镜,3眼选用Piggyback CL,三种镜片矫正视力比框架眼镜明显提高.PMMA虹彩镜和Piggyback CL用于外伤后角膜白斑、术后无晶状体、虹膜严重损伤眼,除显著提高视力外,还明显改善了羞明症状和眼外观.结论在严格的医疗化管理下,利用CL矫正少儿眼外伤术后无晶状体眼的高度屈光不正、屈光参差,恢复双眼视觉是安全、有效的.硬性接触镜(HCL)的视力矫正效果明显优于SCL.     

维族和汉族大学生正视眼眼压及眼球部分生物学参数分析

目的：对双眼为正视眼的维吾尔族与汉族大学生进行眼压及眼球部分生物学参数测定,通过对族别、性别、眼别间比较分析验证两民族间是否存在差异。
　　方法：横断面调查研究。对门诊进行体检的大学生先行双眼裸眼视力检查,然后采用电脑验光仪测量角膜屈光力,再使用裂隙灯及检眼镜检查后纳入符合标准者405例810眼。对纳入对象先采用全自动非接触式眼压计测量眼压,再采用A/B型超声诊断仪测量前房深度、晶状体厚度、玻璃体腔长度及眼轴长度。比较两民族之间、同民族不同性别间、不同民族相同性别间、不同眼别间所测得的眼压及眼球部分生物学参数。
　　结果：维吾尔族与汉族学生眼压、前房深度、晶状体厚度、玻璃体腔长度、眼轴长度差异有统计学意义(P<0.05)。维吾尔族男生与女生前房深度、眼轴长度、角膜屈光力差异有统计学意义(P<0.05)。汉族男生与女生眼轴长度、角膜屈光力差异有统计学意义(P<0.05)。不同眼别间差异无统计学意义(P>0.05)。维吾尔族男生与汉族男生眼压、前房深度、玻璃体腔长度、眼轴长度、晶状体厚度差异有统计学意义(P<0.05)。维吾尔族女生与汉族女生眼压、前房深度、眼轴长度差异有统计学意义(P<0.05)。
　　结论：汉族学生比维吾尔族学生眼压高、前房深、玻璃体腔长、眼轴长、晶状体薄;相同民族男生眼轴长度均较女生长,角膜屈光力比女生小,其中维吾尔族男生比同民族女生前房深。汉族男生较维吾尔族男生眼压高、前房深、玻璃体腔长、眼轴长、晶状体薄;汉族女生较维吾尔族女生眼压高、前房深、眼轴长。右眼与左眼眼压及眼球部分生物学参数比较无差异。     

Congenital ptosis: results of surgical management

PURPOSE: To determine the visual and cosmetic outcome following the surgical correction of isolated congenital ptosis. METHODS: A retrospective review of the outcome of isolated congenital ptosis corrected under the supervision of one surgeon at The Children's Hospital, Camperdown, between January 1983 and January 1993 was examined. Some 65 patients with 80 involved eyes were identified; 30 eyes underwent a levator resection procedure, 40 eyes underwent a brow suspension using donor stored fascia lata, and in 10 eyes a brow suspension was performed using mersilene mesh. RESULTS: In 78 eyes of 63 patients, a good cosmetic result was achieved. In two patients (two eyes) a poor cosmetic result was achieved. These two patients refused further surgery following an undercorrection of their initial ptosis. The recurrence rates for the primary procedures were 16.7% for levator resection procedures, 35% for brow suspension procedures using donor fascia lata, and 30% for brow suspension surgery using mersilene mesh. Some 35.3% of eyes following mersilene slings required further surgery for granulomas and exposed mersilene mesh compared with 6% having similar complications with stored fascia lata. Nine patients (11.25%) had reduced visual acuity (one line or more on the Snellen chart or its equivalent with the other tests used) on the operated side. Only one patient was found to have significant astigmatism. CONCLUSIONS: An acceptable cosmetic result was achieved with one operation in 75.3% of cases. In 20.8% of cases a second operation was required and in 3.9% of cases three or more operations were required. This series supports the view that where possible, levator resection is the preferred form of surgery to correct congenital ptosis. When the levator function is inadequate, brow suspension is performed. The use of donor fascia lata resulted in a good cosmetic appearance with a low occurrence of surgical side effects. Amblyopia, when strictly defined, occurred in 11.25% of eyes despite early surgery for severe cases and intensive amblyopia therapy. Management requires repeated follow up for early detection and introduction of occlusion therapy or surgical ptosis correction.     

An outbreak of Fusarium keratitis associated with contact lens use in the northeastern United States

PURPOSE: To report an outbreak of Fusarium keratitis in contact lens (CL) wearers in the northeastern United States. METHODS: Over a 41-month period, all cases with culture-proven corneal ulceration secondary to Fusarium at 2 tertiary care eye centers were identified through the microbiology departments of each institution, and a retrospective review of charts was performed. Statistical analyses were performed to evaluate a possible association of Fusarium keratitis with specific CL and CL solution brands. RESULTS: Fifteen cases of Fusarium keratitis were reported at the 2 tertiary centers between July 2005 and May 2006 (16.4 cases/yr) compared with 6 cases over the previous 30 months from January 2003 to June 2005 (2.4 cases/yr). All 15 of the more recent cases were CL users, and none had a history of trauma. All 15 patients claimed use of ReNu brand contact lens solution when they developed keratitis. Twelve (80.0%) of 15 patients were Acuvue soft contact lens users. Ten (66.7%) of 15 patients used tap water to rinse their contact lens cases. Six (40.0%) of 15 cases have thus far required corneal transplantation. CONCLUSIONS: The incidence of corneal ulceration secondary to Fusarium has increased sevenfold over the reported 11-month period at 2 tertiary eye care centers in the northeastern United States compared with the previous 30 months. There seems to be an association between the recent outbreak of Fusarium keratitis among CL users and the use of ReNu contact lens solution. Medical treatment of Fusarium keratitis may be ineffective, and emergent penetrating keratoplasty (PKP) may be required in some patients. CL users and their physicians should reconsider the risks of CL use and discuss proper lens care techniques.     

大学生电子产品使用与视疲劳发生的相关性分析

目的　调查大学生视疲劳的患病率及其与电子设备使用之间的关系。方法　2016至2017学年第二学期向全国29个省份（除台湾、青海、西藏、宁夏、新疆）127所大学学生随机分发6000份问卷,问卷内容包含电子设备的依赖情况,电子设备在寝室、家中、交通工具上使用情况以及视疲劳患病情况。使用Logistic回归分析视疲劳危险因素。结果　总计回收有效问卷4848份,其中男2259份,女2589份。结果显示,受调查的大学生人群中视疲劳的患病率为53.5%,女性高于男性,其中33.8%的学生表示已对电子设备产生依赖,在桌前、床上、交通工具上使用电子设备的人分别达到了91.3%、87.6%和74.8%。在使用时间上,中国大学生每天使用手机、平板、电脑等4.0 h以上的达38.3%,每天在床上使用电子设备超过1.0 h的达29.7%,在交通工具上使用≥0.5 h的达49.1%。单因素Logistic回归分析认为性别、电子设备的依赖情况、电子设备在寝室、家中、交通工具上的使用情况等与视疲劳的发生均具有相关性。结论　大学生视疲劳的患病率较高,性别、电子设备的依赖情况、电子设备在不同场景上的使用情况等因素对大学生视疲劳的患病率均有一定的影响。     

Acanthamoeba keratitis: multicentre survey in England 1992-6

AIM—To investigate the frequency, outcomes, and risk factors for acanthamoeba keratitis (AK) in England during the past 4 years.
METHODS—An ophthalmologist in 12 of the 14 regional health authorities (RHAs) coordinated identification of patients in their region presenting with AK between 1 October 1992 and 30 September 1996. Clinical and postal patient questionnaire data were analysed.
RESULTS—243 patients (259 eyes) with an AK diagnosis were identified, equating to an annualised incidence of 0.14 per 100 000 individuals. UK resident patients for each year numbered 50, 71, 73, and 32 respectively. Among patients with sufficient data 170/237 (72%) were diagnosed early (within 30 days of presentation), 197/218 (90%) were treated with polyhexamethyl biguanide and/or chlorhexidine, and 40/243 (16%) underwent surgery. Visual acuities of 6/12 or better were achieved by 222/259 (86%) eyes, including 84 eyes of patients under review or lost to follow up. Non-contact lens (CL) wearers were associated with delayed diagnosis, increased need for surgery and a poorer visual outcome (only 10/18 eyes, 56%, achieved 6/12 acuity). 225/243 (93%) patients were CL wearers, and 205/243 (84%) were soft CL (SCL) users. Among SCL user respondents, previously identified risk factors—swimming with CL (47/138, 34%), non-sterile CL rinsing (11/138, 8%), omitted disinfection (85/138, 62%), and chlorine release disinfection (65/138, 47%)—were identified for 125/138 (91%) patients.
CONCLUSIONS—Earlier diagnosis and more effective medical therapy have improved the prognosis for most AK patients. The study demonstrates the highly preventable nature of the disease: 91% of the SCL wearers could have avoided the disease by refraining from inadvisable practices, and a marked fall in frequency was seen after intensive media attention to AK, possibly in conjunction with increasing penetrance of new CL products. Since the frequency of AK appears to be largely determined by the ever changing trends in CL use, continued monitoring is indicated.

Keywords: keratitis; Acanthamoeba; multicentre survey; England     

The Epidemiology of Cosmetic Treatments for Corneal Opacities in a Korean Population

Purpose

To describe etiologies and clinical characteristics of corneal opacities leading patients to seek cosmetic treatments.

Methods

The medical records of 401 patients who presented for cosmetic improvement in corneal opacities between May 2004 and July 2007 were retrospectively reviewed. The following parameters were analyzed: age, gender, cause of corneal opacity, time course of the corneal disease, associated diseases, prior and current cosmetic treatments, visual acuity, location and depth of the corneal opacity, and the presence of either corneal neovascularization or band keratopathy. A single practitioner examined all patients.

Results

The most common causes of corneal opacity were ocular trauma (203 eyes, 50.6%), retinal disease (62 eyes, 15.5%), measles (38 eyes, 9.5%), and congenital etiologies (22 eyes, 5.5%). Prior treatments included iris colored contact lenses (125 eyes, 31.1%) and corneal tattooing (34 eyes, 8.46%). A total of 321 of 401 eyes underwent cosmetic treatment for corneal opacities. The most common treatment performed after the primary visit was corneal tattooing (261 eyes, 64.92%).

Conclusions

This is the first study to investigate the causes and clinical characteristics of patients presenting for cosmetic treatment of corneal opacities rather than for functional improvement. Various cosmetic interventions are available for patients with corneal opacities, and these should be individualized for the needs of each patient.     

Patching fellow eyes during subjective night does not prevent disruption to minus lens compensation in constant light-reared chicks

PURPOSE: This study re-examined an earlier claim that monocular patching during subjective night (i.e. patched at the usual time that night would occur) in the chicks reared in continuous lighting (CL), offered unpatched eyes some protection from the ocular effects of CL. It also examined whether this monocular patching protected unpatched eyes against the disruptive effect of CL on compensation to minus lenses. METHODS: Hatchling White-Leghorn chicks were reared in either constant or diurnal lighting conditions (n=28) for 2 weeks. Some CL chicks had their right eyes patched every night during the entire study. Lenses of either +10 or -10D power were fitted to the unpatched eyes of some patched chicks at the beginning of the second week. Retinoscopy, IR photo-keratometry and high-frequency A-scan ultrasonography were used to track refractions, corneal radius of curvature and ocular axial dimensions respectively; data were collected on experimental days 0, 7, 9 and 14. RESULTS: The patched eyes were completely protected from the ocular growth effects of CL, i.e. accelerated posterior segment (vitreous chamber) growth and inhibited anterior segment growth. Although the unpatched eyes showed no protection from the anterior chamber effects of CL, they were completely protected from the effects of CL on vitreous chamber growth. Nonetheless, the response to the -10D lenses was disrupted in unpatched eyes, which responded in the wrong direction for compensation (+5.5+/-0.25D more hyperopic than no lens-unpatched eyes). The response to the +10D lenses was preserved (+9.25+/-0.25D more hyperopic than no lens-unpatched eyes). CONCLUSION: These data provide further support for local control of emmetropization, as reflected in compensatory lens responses, but point to additional influences on eye growth as reflected in CL-induced ocular changes.     

Effects of topical dorzolamide on IOP after phacoemulsification with different types of ophthalmic viscosurgical devices

PURPOSE: To evaluate the effect of topical dorzolamide on postoperative intraocular pressure (IOP) after routine phacoemulsification surgery with different type of ophthalmic viscosurgical device (OVD). METHODS: Patients who were scheduled for phacoemulsification with intraocular lens (IOL) implantation were evenly divided into four groups. Group I (83 eyes) received one drop of topical dorzolamide immediately after surgery and 1.4% NaHa (BD Visc) was used as a cohesive OVD during IOL implantation. Group II (83 eyes) did not receive any topical antiglaucoma medication after operation and 1.4% NaHa was used as a cohesive OVD. Group III (83 eyes) received topical dorzolamide and 1% NaHa (Healon) was used, and Group IV (83 eyes) did not receive any topical and 1% NaHa was used in operation. Mean postoperative IOPs were compared between groups. RESULTS: Eyes with 1.4% NaHa usage (18.2+/-9.2 mmHg) had higher mean postoperative IOPs than eyes with 1% NaHa usage (15.5+/-5.3 mmHg) (p=0.002). Mean postoperative IOPs were lower in eyes with dorzolamide application (15.6+/-7.2 mmHg) than in eyes without any medication (18.1+/-8.5 mmHg) both in eyes with 1.4% NaHa and 1% NaHa usage (p=0.003). Dorzolamide application caused an average 2.5 mm decrease in mean postoperative IOPs in both groups. CONCLUSIONS: Effects of OVDs on IOP rises after phacoemulsification surgery are closely related to their molecular structure. Increase in viscosity rendered higher postoperative IOP increments. However, topical dorzolamide application effectively reduced postoperative IOP increments in eyes with both Healon and BD Visc use.     

Excimer laser photorefractive keratectomy for patients with contact lens intolerance caused by dry eye.

AIMS/BACKGROUND: To evaluate epithelial wound healing and visual outcome of excimer laser photorefractive keratectomy (PRK) performed on high myopic eyes with contact lens intolerance due to dry eye. METHODS: PRK was performed on two groups of patients with non-Sjogren's dry eye: group A (-6 D to -9.5 D, 11 patients, 17 eyes) and group B (-11.5 D to -19.5 D, 11 patients, 16 eyes) in an attempt to eliminate the use of contact lenses (CL). The intended correction was full in group A and 10 D in group B. RESULTS: Uncorrected visual acuity in group A was better than 20/40 in 12 (80.0%) of 15 eyes at 6 months and in 10 (90.9%) of 11 eyes at 1 year. Fourteen (92.8%) of 17 eyes in group A and four (25.0%) of 16 eyes in group B achieved refraction within plus or minus 1 D of the intended correction at 6 months. Re-epithelialisation was complete in 4 days, and epithelial cell area and permeability returned to the preoperative level within 1 month in all cases. All patients in group A were able to eliminate CL, whereas in group B, one patient needed spectacles for residual myopia and two patients resumed CL use because of regression. One eye with severe subepithelial scar formation and one eye with macular haemorrhage were observed in group B. CONCLUSION: Our results suggest that PRK is effective for patients with high myopia (-6 D to approximately -10 D) and CL intolerance due to dry eye. Further studies are required to improve predictability and to prevent complications in PRK for very high myopia (> -10 D).     

Disposable contact lens use as a risk factor for microbial keratitis

AIMS—A case-control study was performed to evaluate soft contact lens (SCL) wear modality as a risk factor for microbial keratitis.
METHODS—Contact lens wearers presenting as new patients to Moorfields Eye Hospital accident and emergency department during a 12 month period completed a self administered questionnaire detailing demographic data and contact lens use habits. Cases were patients with a clinical diagnosis of SCL related microbial keratitis. Controls were SCL users attending with disorders unrelated to contact lens wear. Odds ratios (estimates of relative risks) and 95% confidence limits (CL) were calculated through multivariable logistic regression analysis.
RESULTS—There were 89 cases and 566 controls. A substantially increased risk with 1-4 weekly disposable SCL compared with non-disposable SCL was identified among both daily wear (DW) (odds ratio =3.51, 95% CL 1.60-7.66, p=0.002) and extended wear (odds ratio 4.76, 95% CL 1.52-14.87, p=0.007) users after adjustment for demographic, lens use and hygiene variables. Other significant factors among DW users were "occasional" overnight use, use of chlorine based (as opposed to other chemical) systems in combination with poor storage case hygiene, and irregular disinfection.
CONCLUSION—Properties of some disposable SCL may be partly responsible for these excess risks. It is also possible, however, that this finding is largely a reflection of widespread complacency among patients and practitioners with respect to disposable SCL fitting and use.

Keywords: microbial keratitis; disposable contact lenses     

Effect of soft contact lens on central visual field

The effect of soft contact lenses (CLs) and spectacles on central visual fields was assessed in 48 eyes. Forty-three eyes (89.5%) showed smaller pattern standard deviation in CL wearers than five eyes (10.5%) with spectacles. In addition, 38 CL wearers (79%) showed higher positive mean deviation values than 10 eyes (20.8%) with spectacles. Findings indicate the pattern of visual fields shifts toward normalcy in CL wearers. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article. The authors also do not discuss the use of off-label products, which includes unlabeled, unapproved, or investigative products or devices.     

Constant light rearing disrupts compensation to imposed- but not induced-hyperopia and facilitates compensation to imposed myopia in chicks

PURPOSE: While rearing chicks in constant light (CL) inhibits anterior segment growth, these conditions also induce excessive enlargement of the vitreous chamber. The mechanisms underlying these effects are poorly understood although it has been speculated that the enlarged vitreous chambers are a product of emmetropization, a compensatory response to the altered anterior segments. We examined the ability of eyes to compensate to defocusing lenses in CL as a direct test of their ability to emmetropize. We also studied recovery responses, i.e. from lens-induced changes in CL as well as CL-induced changes alone or combined with lens-induced changes in eyes returned to normal diurnal lighting (NL). METHODS: Hatchling White-Leghorn chicks were reared in either CL or NL (control) lighting conditions (n=36) for 2 weeks, with lenses of either +10 or -10D power fitted to one eye of all chicks at the beginning of the second week. The lenses were removed at the end of the same week, at which time some CL chicks (n=14) were shifted to NL, the rest of the chicks remaining in their respective original lighting conditions. Retinoscopy, IR photo-keratometry and high-frequency A-scan ultrasonography were used to track refractions, corneal radii of curvature and ocular axial dimensions, respectively; data were collected on experimental days 0, 7, 9, 14 and 21. RESULTS: Under CL, eyes showed near normal, albeit slightly exaggerated responses to +10D lenses while the response to -10D lenses was disrupted. With +10D lenses, lens-wearing eyes became more hyperopic (RE), and had shorter vitreous chambers (VC) and optical axial lengths (OL) relative to their fellows by the end of the lens period [RE: +10.5+/-1.5D, CL, +8.25+/-2.5D, NL; VC: -0.363+/-0.129mm, CL; -0.306+/-0.110mm, NL; OL: -0.493+/-0.115mm, CL, -0.379+/-0.106mm, NL (mean interocular difference+/-SD)]. With -10D lenses, the NL group showed a myopic shift in RE and increased elongation of both VC depth and OL (RE: -10.75+/-2.0D; VC depth: 0.554+/-0.097mm; OL: 0.746+/-0.166mm), while the CL group showed a small hyperopic shift in RE (+4.0+/-6.0D). Nonetheless, CL eyes were able to recover from lens-induced hyperopia, whether they were left in CL or returned to NL. One week of exposure to NL was sufficient to reverse the effects of 2 weeks of CL on anterior and vitreous chamber dimensions. CONCLUSION: CL impairs emmetropization. Specifically, it disrupts compensation to lens-imposed hyperopia but not imposed myopia. However, CL eyes are able to recover from lens-induced hyperopia, suggesting that the mechanisms underlying the compensatory responses to defocusing lenses are different from those involved in recovery responses. The ocular growth effects of CL on young eyes are reversible under NL.