Increasing evidence points out that long-term treatment with selective 5-HT reuptake inhibitors (SSRIs), that effectively block 5-HT reuptake by blocking SERT and enhance 5-HT tone, can produce a range of adverse effects on vision including reduced visual acuity, night blindness, glaucoma and optic neuropathy [46, 47]. This evidence concerns the gene SLC6A4 and night blindness.