What is the thickening of eye lens?

Figure 1.

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What causes eye lens thickening?
What is eye lens thickness?
What happens when lens becomes thicker?

The prevalence of myopia among three nationwide surveys performed (1995, 2000, and 2006) in Taiwan.

Figure 1.

The prevalence of myopia among three nationwide surveys performed (1995, 2000, and 2006) in Taiwan.

Figure 2.

The ocular components of schoolchildren in the 2006 survey. (A) The mean AL increased with age. (B) The mean ACD increased slightly with age. (C) The mean LT decreased with age from the ages of 7 to 11 and then increased with age after the age of 12. (D) The mean K increased slightly with age.

Figure 2.

Figure 3.

Mean of ocular components of hyperopic (≥ +0.5 D), emmetropic (+0.25 to −0.25 D), and myopic (< −0.25 D) eyes in 2006. (A) No significant difference was found in mean K among the three groups. (B) Myopic eyes showed a deeper mean ACD than did emmetropic and hyperopic eyes. (C) Myopic eyes showed the least mean LT of the three groups. (D) Myopic eyes had the longest mean AL.

Figure 3.

Figure 4.

The mean LT among in each myopic refraction group showed decreased LT from age of 7 to 11, and subsequently increased with age.

Figure 4.

The mean LT among in each myopic refraction group showed decreased LT from age of 7 to 11, and subsequently increased with age.

Figure 5.

LT in highly myopic eyes (< −6.0 D) increased with age and in moderately hyperopic eyes (> +3.0 D), decreased very quickly from age of 7 to 11, and then increased from 12 onward.

Figure 5.

LT in highly myopic eyes (< −6.0 D) increased with age and in moderately hyperopic eyes (> +3.0 D), decreased very quickly from age of 7 to 11, and then increased from 12 onward.

Figure 6.

Changes in the mean LT in each age group. LT was thinner at younger ages and thicker at 18 years.

Figure 6.

Changes in the mean LT in each age group. LT was thinner at younger ages and thicker at 18 years.

Figure 7.

The mean ocular component ratios in different refractive groups. (A) Myopic eyes showed a decrease in the mean ACD/AL ratio after the age of 12, but the decrease was variable. (B) Myopic eyes showed a decrease in the mean LT/AL ratio with age, but the ratio in emmetropic and hyperopic eyes was stable with age. (C) Myopic eyes also showed a decrease in the mean anterior segment/AL ratio with age, but the ratio in emmetropic and hyperopic eyes was stable with age.

Figure 7.

Table 1.

The Mean Refraction, ACD, LT, and AL of Schoolchildren in Each Age Group

Table 1.

The Mean Refraction, ACD, LT, and AL of Schoolchildren in Each Age Group

Age (y)	Girls				Boys
	REF (D)	ACD (mm)	LT (mm)	AL (mm)	REF (D)	ACD (mm)	LT (mm)	AL (mm)
7	0.25 ± 1.04	3.45 ± 0.33	3.44 ± 0.26	22.46 ± 0.79	0.24 ± 0.95	3.59 ± 0.31	3.45 ± 0.23	23.02 ± 0.71
8	−0.13 ± 1.35	3.49 ± 0.33	3.43 ± 0.26	22.80 ± 0.87	−0.18 ± 1.33	3.58 ± 0.35	3.42 ± 0.27	23.27 ± 0.90
9	−0.41 ± 1.58	3.54 ± 0.34	3.39 ± 0.24	23.00 ± 0.98	−0.47 ± 1.37	3.61 ± 0.35	3.40 ± 0.24	23.49 ± 0.89
10	−0.85 ± 1.77	3.60 ± 0.34	3.34 ± 0.21	23.28 ± 0.96	−0.63 ± 1.54	3.65 ± 0.37	3.36 ± 0.26	23.79 ± 1.00
11	−1.19 ± 1.88	3.67 ± 0.34	3.32 ± 0.24	23.53 ± 1.05	−0.86 ± 1.64	3.72 ± 0.33	3.32 ± 0.23	23.89 ± 1.00
12	−1.59 ± 2.04	3.68 ± 0.35	3.33 ± 0.22	23.72 ± 1.12	−1.27 ± 2.09	3.73 ± 0.36	3.34 ± 0.26	24.23 ± 1.11
13	−1.74 ± 2.05	3.64 ± 0.34	3.39 ± 0.27	23.85 ± 1.11	−1.55 ± 2.10	3.71 ± 0.37	3.38 ± 0.26	24.36 ± 1.07
14	−2.32 ± 2.46	3.63 ± 0.36	3.44 ± 0.27	24.14 ± 1.19	−1.90 ± 2.32	3.70 ± 0.37	3.38 ± 0.29	24.47 ± 1.14
15	−2.59 ± 2.35	3.63 ± 0.37	3.40 ± 0.26	24.20 ± 1.21	−2.19 ± 2.27	3.71 ± 0.38	3.41 ± 0.26	24.61 ± 1.19
16	−2.31 ± 2.51	3.68 ± 0.30	3.45 ± 0.22	24.18 ± 1.18	−2.31 ± 2.55	3.76 ± 0.29	3.35 ± 0.21	24.37 ± 1.16
17	−2.80 ± 2.80	3.65 ± 0.27	3.47 ± 0.21	24.34 ± 1.27	−2.60 ± 2.95	3.85 ± 0.36	3.33 ± 0.25	24.49 ± 1.20
18	−3.27 ± 2.63	3.68 ± 0.29	3.50 ± 0.20	24.55 ± 1.23	−4.06 ± 2.70	3.64 ± 0.33	3.62 ± 0.23	25.16 ± 1.19

Table 2.

Mean Ocular Component Ratios

Table 2.

Mean Ocular Component Ratios

	Hyperopia	Emmetropia	Myopia
ACD/AL	0.1542	0.1537	0.152
LT/AL	0.152	0.147	0.139
Anterior Seg/AL	0.305	0.301	0.292

Table 3.

Ratios in Emmetropic Eyes in the Different Age Groups

Table 3.

Ratios in Emmetropic Eyes in the Different Age Groups

Age Range (y)	LT/AL Ratio			ACD/AL Ratio
	Male	Female	Mean	Male	Female	Mean
7–18	0.150	0.144	0.147	0.156	0.152	0.154
21–30	0.164	0.160	0.162	0.132	0.123	0.128
31–40	0.175	0.176	0.176	0.123	0.115	0.119
41–50	0.183	0.181	0.182	0.113	0.108	0.111
51–60	0.187	0.186	0.187	0.111	0.109	0.110
61–70	0.191	0.198	0.195	0.106	0.100	0.103
Average	0.177	0.179		0.119	0.115

Table 4.

The Mean Anterior Segment [(LT + ACD)/AL] Ratios in Emmetropic Eyes by Age Group

Table 4.

The Mean Anterior Segment [(LT + ACD)/AL] Ratios in Emmetropic Eyes by Age Group

Age Range (y)	Male	Female	Mean
7–18	0.305	0.297	0.301
21–30	0.295	0.283	0.289
31–40	0.298	0.291	0.295
41–50	0.298	0.290	0.294
51–60	0.298	0.295	0.297
61–70	0.297	0.297	0.297
Average	0.297	0.295

What causes eye lens thickening?

As we age, proteins clump together and begin to cloud a small area of the lens. Over time, the cataract may grow larger, clouding more of the lens, making vision more and more difficult.

What is eye lens thickness?

Adler² reported that the thickness of the normal human lens was 4 mm at the age of 20 years, 4.3 mm at the age 40 of years, 4.45 mm at the age of 50 years, 4.7 mm at the age of 60 years, and increased in thickness to beyond 4.7 mm after 60 years of age.